diff --git a/.eslintrc b/.eslintrc
index 24f9ab5..40d7e9b 100644
--- a/.eslintrc
+++ b/.eslintrc
@@ -47,6 +47,7 @@
     "no-var": "error",
     "prefer-const": "error",
     "no-trailing-spaces": "error",
-    "react/prop-types": 0
+    "react/prop-types": 0,
+    "max-len": "warn" 
   }
 }
\ No newline at end of file
diff --git a/lib/sympto/minus-8-day-rule.js b/lib/sympto/minus-8-day-rule.js
new file mode 100644
index 0000000..2964b37
--- /dev/null
+++ b/lib/sympto/minus-8-day-rule.js
@@ -0,0 +1,26 @@
+import { LocalDate } from 'js-joda'
+import getNfpStatus from './index'
+
+export default function (previousCycles) {
+  const fhms = previousCycles
+    .map(cycle => {
+      const status = getNfpStatus({ cycle })
+      if (status.temperatureShift) {
+        const day = status.temperatureShift.firstHighMeasurementDay
+        const firstCycleDayDate = LocalDate.parse(cycle[0].date)
+        const fhmDate = LocalDate.parse(day.date)
+        return fhmDate.compareTo(firstCycleDayDate) + 1
+      }
+      return null
+    })
+    .filter(val => typeof val === 'number')
+
+  const preOvuLength = Math.min(...fhms) - 8
+
+  // pre ovu length may only be lengthened if we have more than 12 previous fhms
+  // if pre ovu length is less than 5, it shortened even with fewer prev fhms
+  if (preOvuLength < 5) return preOvuLength
+  if (fhms.length >= 12) return preOvuLength
+
+  return null
+}
\ No newline at end of file
diff --git a/lib/sympto/pre-ovulatory.js b/lib/sympto/pre-ovulatory.js
index 7d6e15a..01efb19 100644
--- a/lib/sympto/pre-ovulatory.js
+++ b/lib/sympto/pre-ovulatory.js
@@ -1,20 +1,21 @@
 import { LocalDate } from "js-joda"
+import apply8DayRule from './minus-8-day-rule'
 
 export default function(cycle, previousCycles) {
-  // TODO handle no previous cycles
   let preOvuPhaseLength = 5
 
-  //TODO make sure it handles weird cases like fhm < 9
   const minus8DayRuleResult = apply8DayRule(previousCycles)
   if (minus8DayRuleResult) preOvuPhaseLength = minus8DayRuleResult
 
   const startDate = LocalDate.parse(cycle[0].date)
-  const preOvuPhaseEndDate = startDate.plusDays(preOvuPhaseLength - 1).toString()
-  const maybePreOvuDays = cycle.slice(0, 5).filter(d => d.date <= preOvuPhaseEndDate)
+  const preOvuEndDate = startDate.plusDays(preOvuPhaseLength - 1).toString()
+  const maybePreOvuDays = cycle.slice(0, preOvuPhaseLength).filter(d => {
+    return d.date <= preOvuEndDate
+  })
   const preOvulatoryDays = getDaysUntilFertileMucus(maybePreOvuDays)
   let endDate
   if (preOvulatoryDays.length === maybePreOvuDays.length) {
-    endDate = preOvuPhaseEndDate
+    endDate = preOvuEndDate
   } else {
     endDate = preOvulatoryDays[preOvulatoryDays.length - 1].date
   }
@@ -31,11 +32,12 @@ export default function(cycle, previousCycles) {
 }
 
 function getDaysUntilFertileMucus(days) {
-  const firstFertileMucusDayIndex = days.findIndex(day => day.mucus && day.mucus.value > 1)
+  const firstFertileMucusDayIndex = days.findIndex(day => {
+    return day.mucus && day.mucus.value > 1
+  })
+
   if (firstFertileMucusDayIndex > -1) {
     return days.slice(0, firstFertileMucusDayIndex)
   }
   return days
-}
-
-function apply8DayRule(previousCycles) {}
\ No newline at end of file
+}
\ No newline at end of file
diff --git a/test/sympto/fixtures.js b/test/sympto/fixtures.js
index 5ac51be..ce096fa 100644
--- a/test/sympto/fixtures.js
+++ b/test/sympto/fixtures.js
@@ -7,17 +7,31 @@ function convertToSymptoFormat(val) {
   return sympto
 }
 
-export const cycleWithTempShift = [36.6, 36.6, 36.6, 36.6, 36.6, 36.6, 36.8, 36.8, 36.8]
-  .map(num => ({ date: '2018-06-01', temperature: num }))
-  .map(convertToSymptoFormat)
-cycleWithTempShift.unshift({date: '2018-05-30', bleeding: { value: 2 }})
+export const cycleWithFhm = [
+  { date: '2018-06-01', temperature: 36.6, bleeding: 2 },
+  { date: '2018-06-02', temperature: 36.65 },
+  { date: '2018-06-04', temperature: 36.6 },
+  { date: '2018-06-05', temperature: 36.55 },
+  { date: '2018-06-06', temperature: 36.7, mucus: 0 },
+  { date: '2018-06-13', temperature: 36.8, mucus: 4 },
+  { date: '2018-06-15', temperature: 36.9, mucus: 2 },
+  { date: '2018-06-17', temperature: 36.9, mucus: 2 },
+  { date: '2018-06-17', temperature: 36.9, mucus: 2 },
+  { date: '2018-06-18', temperature: 36.9, mucus: 2 }
+].map(convertToSymptoFormat)
 
-export const cycleWithoutTempShift = [36.6, 36.6, 36.6, 36.6, 36.6, 36.6, 36.8, 36.8]
-  .map(num => ({ date: '2018-06-01', temperature: num }))
-  .map(convertToSymptoFormat)
-cycleWithoutTempShift.unshift({date: '2018-05-30', bleeding: { value: 2 }})
+export const cycleWithoutFhm = [
+  { date: '2018-06-01', temperature: 36.6, bleeding: 2 },
+  { date: '2018-06-02', temperature: 36.65 },
+  { date: '2018-06-04', temperature: 36.6 },
+  { date: '2018-06-05', temperature: 36.55 },
+  { date: '2018-06-06', temperature: 36.7, mucus: 0 },
+  { date: '2018-06-09', temperature: 36.8, mucus: 4 },
+  { date: '2018-06-10', temperature: 36.9, mucus: 2 },
+  { date: '2018-06-13', temperature: 36.9, mucus: 2 }
+].map(convertToSymptoFormat)
 
-export const cycleWithTempAndMucusShift = [
+export const longAndComplicatedCycle = [
   { date: '2018-06-01', temperature: 36.6, bleeding: 2 },
   { date: '2018-06-02', temperature: 36.65 },
   { date: '2018-06-04', temperature: 36.6 },
@@ -224,4 +238,19 @@ export const fhmOnDay12 = [
   { date: '2018-06-12', temperature: 36.8, mucus: 3 },
   { date: '2018-06-14', temperature: 36.9, mucus: 2 },
   { date: '2018-06-17', temperature: 36.9, mucus: 2 },
+  { date: '2018-06-18', temperature: 36.9, mucus: 2 },
 ].map(convertToSymptoFormat)
+
+export const fhmOnDay15 = [
+  { date: '2018-06-01', temperature: 36.6, bleeding: 2 },
+  { date: '2018-06-02', temperature: 36.65 },
+  { date: '2018-06-04', temperature: 36.6 },
+  { date: '2018-06-05', temperature: 36.55 },
+  { date: '2018-06-06', temperature: 36.7, mucus: 0 },
+  { date: '2018-06-09', temperature: 36.5, mucus: 2 },
+  { date: '2018-06-10', temperature: 36.4, mucus: 3 },
+  { date: '2018-06-15', temperature: 36.8, mucus: 3 },
+  { date: '2018-06-16', temperature: 36.9, mucus: 2 },
+  { date: '2018-06-17', temperature: 36.9, mucus: 2 },
+  { date: '2018-06-18', temperature: 36.9, mucus: 2 },
+].map(convertToSymptoFormat)
\ No newline at end of file
diff --git a/test/sympto/index.spec.js b/test/sympto/index.spec.js
index 4b00183..bbb66d4 100644
--- a/test/sympto/index.spec.js
+++ b/test/sympto/index.spec.js
@@ -2,10 +2,10 @@ import chai from 'chai'
 import getSensiplanStatus from '../../lib/sympto'
 import { AssertionError } from 'assert'
 import {
-  cycleWithoutTempShift,
-  cycleWithTempAndMucusShift,
+  cycleWithoutFhm,
+  longAndComplicatedCycle,
   cycleWithTempAndNoMucusShift,
-  cycleWithTempShift,
+  cycleWithFhm,
   cycleWithoutAnyShifts,
   fiveDayCycle,
   cycleWithEarlyMucus,
@@ -14,7 +14,8 @@ import {
   fhm5DaysAfterMucusPeak,
   mucusPeak5DaysAfterFhm,
   mucusPeakTwoDaysBeforeFhm,
-  fhmOnDay12
+  fhmOnDay12,
+  fhmOnDay15
 } from './fixtures'
 
 const expect = chai.expect
@@ -24,7 +25,7 @@ describe('sympto', () => {
     it('with no shifts detects only peri-ovulatory', function () {
       const status = getSensiplanStatus({
         cycle: cycleWithoutAnyShifts,
-        previousCycles: [cycleWithoutTempShift]
+        previousCycles: [cycleWithoutFhm,]
       })
 
       expect(status).to.eql({
@@ -38,10 +39,10 @@ describe('sympto', () => {
       })
     })
 
-    it('with shifts detects only peri-ovulatory and post-ovulatory', function () {
+    it('with shifts detects only peri-ovulatory and post-ovulatory', () => {
       const status = getSensiplanStatus({
-        cycle: cycleWithTempAndMucusShift,
-        previousCycles: [cycleWithoutTempShift]
+        cycle: longAndComplicatedCycle,
+        previousCycles: [cycleWithoutFhm,]
       })
 
       expect(status.temperatureShift).to.be.an('object')
@@ -51,14 +52,16 @@ describe('sympto', () => {
       expect(status.phases.periOvulatory).to.eql({
         start: { date: '2018-06-01' },
         end: { date: '2018-06-21', time: '18:00' },
-        cycleDays: cycleWithTempAndMucusShift.filter(({date}) => date <= '2018-06-21')
+        cycleDays: longAndComplicatedCycle
+          .filter(({date}) => date <= '2018-06-21')
       })
       expect(status.phases.postOvulatory).to.eql({
         start: {
           date: '2018-06-21',
           time: '18:00'
         },
-        cycleDays: cycleWithTempAndMucusShift.filter(({date}) => date >= '2018-06-21')
+        cycleDays: longAndComplicatedCycle
+          .filter(({date}) => date >= '2018-06-21')
       })
     })
   })
@@ -67,7 +70,7 @@ describe('sympto', () => {
       it('according to 5-day-rule', function () {
         const status = getSensiplanStatus({
           cycle: fiveDayCycle,
-          previousCycles: [cycleWithTempShift]
+          previousCycles: [cycleWithFhm]
         })
 
         expect(Object.keys(status.phases).length).to.eql(1)
@@ -80,29 +83,31 @@ describe('sympto', () => {
       })
 
     })
-    describe('with no shifts detects pre- and peri-ovulatory phase', function () {
+    describe('with no shifts detects pre- and peri-ovulatory phase', () => {
       it('according to 5-day-rule', function () {
         const status = getSensiplanStatus({
           cycle: cycleWithTempAndNoMucusShift,
-          previousCycles: [cycleWithTempShift]
+          previousCycles: [cycleWithFhm]
         })
 
         expect(Object.keys(status.phases).length).to.eql(2)
         expect(status.assumeFertility).to.be.true()
         expect(status.phases.preOvulatory).to.eql({
-          cycleDays: cycleWithTempAndNoMucusShift.filter(({date}) => date <= '2018-06-05'),
+          cycleDays: cycleWithTempAndNoMucusShift
+            .filter(({date}) => date <= '2018-06-05'),
           start: { date: '2018-06-01' },
           end: { date: '2018-06-05' }
         })
         expect(status.phases.periOvulatory).to.eql({
-          cycleDays: cycleWithTempAndNoMucusShift.filter(({date}) => date > '2018-06-05'),
+          cycleDays: cycleWithTempAndNoMucusShift
+            .filter(({date}) => date > '2018-06-05'),
           start: { date: '2018-06-06' }
         })
       })
       it('according to 5-day-rule with shortened pre-phase', function () {
         const status = getSensiplanStatus({
           cycle: cycleWithEarlyMucus,
-          previousCycles: [cycleWithTempShift]
+          previousCycles: [cycleWithFhm]
         })
 
         expect(Object.keys(status.phases).length).to.eql(2)
@@ -121,24 +126,27 @@ describe('sympto', () => {
     describe('with shifts detects pre- and peri-ovulatory phase', function () {
       it('according to 5-day-rule', function () {
         const status = getSensiplanStatus({
-          cycle: cycleWithTempAndMucusShift,
-          previousCycles: [cycleWithTempShift]
+          cycle: longAndComplicatedCycle,
+          previousCycles: [cycleWithFhm]
         })
 
         expect(Object.keys(status.phases).length).to.eql(3)
         expect(status.assumeFertility).to.be.false()
         expect(status.phases.preOvulatory).to.eql({
-          cycleDays: cycleWithTempAndMucusShift.filter(({date}) => date <= '2018-06-05'),
+          cycleDays: longAndComplicatedCycle
+            .filter(({date}) => date <= '2018-06-05'),
           start: { date: '2018-06-01' },
           end: { date: '2018-06-05' }
         })
         expect(status.phases.periOvulatory).to.eql({
-          cycleDays: cycleWithTempAndMucusShift.filter(({date}) => date > '2018-06-05' && date <= '2018-06-21'),
+          cycleDays: longAndComplicatedCycle
+            .filter(({date}) => date > '2018-06-05' && date <= '2018-06-21'),
           start: { date: '2018-06-06' },
           end: { date: '2018-06-21', time: '18:00'}
         })
         expect(status.phases.postOvulatory).to.eql({
-          cycleDays: cycleWithTempAndMucusShift.filter(({date}) => date >= '2018-06-21'),
+          cycleDays: longAndComplicatedCycle
+            .filter(({date}) => date >= '2018-06-21'),
           start: { date: '2018-06-21', time: '18:00'}
         })
       })
@@ -147,10 +155,10 @@ describe('sympto', () => {
   })
 
   describe('combining first higher measurment and mucus peak', () => {
-    it('with fhM + mucus peak on same day finds correct start of post-ovu phase', () => {
+    it('with fhM + mucus peak on same day finds start of postovu phase', () => {
       const status = getSensiplanStatus({
         cycle: mucusPeakAndFhmOnSameDay,
-        previousCycles: [cycleWithTempShift]
+        previousCycles: [cycleWithFhm]
       })
 
       expect(status.temperatureShift).to.be.an('object')
@@ -160,28 +168,31 @@ describe('sympto', () => {
       expect(status.phases.preOvulatory).to.eql({
         start: { date: '2018-06-01' },
         end: { date: '2018-06-05' },
-        cycleDays: mucusPeakAndFhmOnSameDay.filter(({date}) => date <= '2018-06-05')
+        cycleDays: mucusPeakAndFhmOnSameDay
+          .filter(({date}) => date <= '2018-06-05')
       })
       expect(status.phases.periOvulatory).to.eql({
         start: { date: '2018-06-06' },
         end: { date: '2018-06-21', time: '18:00' },
-        cycleDays: mucusPeakAndFhmOnSameDay.filter(({date}) => {
-          return date > '2018-06-05' && date <= '2018-06-21'
-        })
+        cycleDays: mucusPeakAndFhmOnSameDay
+          .filter(({date}) => {
+            return date > '2018-06-05' && date <= '2018-06-21'
+          })
       })
       expect(status.phases.postOvulatory).to.eql({
         start: {
           date: '2018-06-21',
           time: '18:00'
         },
-        cycleDays: mucusPeakAndFhmOnSameDay.filter(({date}) => date >= '2018-06-21')
+        cycleDays: mucusPeakAndFhmOnSameDay
+          .filter(({date}) => date >= '2018-06-21')
       })
     })
 
     it('with fhM 2 days before mucus peak waits for end of mucus eval', () => {
       const status = getSensiplanStatus({
         cycle: fhmTwoDaysBeforeMucusPeak,
-        previousCycles: [cycleWithTempShift]
+        previousCycles: [cycleWithFhm]
       })
 
       expect(status.temperatureShift).to.be.an('object')
@@ -191,28 +202,31 @@ describe('sympto', () => {
       expect(status.phases.preOvulatory).to.eql({
         start: { date: '2018-06-01' },
         end: { date: '2018-06-05' },
-        cycleDays: fhmTwoDaysBeforeMucusPeak.filter(({date}) => date <= '2018-06-05')
+        cycleDays: fhmTwoDaysBeforeMucusPeak
+          .filter(({date}) => date <= '2018-06-05')
       })
       expect(status.phases.periOvulatory).to.eql({
         start: { date: '2018-06-06' },
         end: { date: '2018-06-26', time: '18:00' },
-        cycleDays: fhmTwoDaysBeforeMucusPeak.filter(({date}) => {
-          return date > '2018-06-05' && date <= '2018-06-26'
-        })
+        cycleDays: fhmTwoDaysBeforeMucusPeak
+          .filter(({date}) => {
+            return date > '2018-06-05' && date <= '2018-06-26'
+          })
       })
       expect(status.phases.postOvulatory).to.eql({
         start: {
           date: '2018-06-26',
           time: '18:00'
         },
-        cycleDays: fhmTwoDaysBeforeMucusPeak.filter(({date}) => date >= '2018-06-26')
+        cycleDays: fhmTwoDaysBeforeMucusPeak
+          .filter(({date}) => date >= '2018-06-26')
       })
     })
 
     it('with another mucus peak 5 days after fHM ignores it', () => {
       const status = getSensiplanStatus({
         cycle: mucusPeak5DaysAfterFhm,
-        previousCycles: [cycleWithTempShift]
+        previousCycles: [cycleWithFhm]
       })
 
       expect(status.temperatureShift).to.be.an('object')
@@ -222,28 +236,31 @@ describe('sympto', () => {
       expect(status.phases.preOvulatory).to.eql({
         start: { date: '2018-06-01' },
         end: { date: '2018-06-01' },
-        cycleDays: mucusPeak5DaysAfterFhm.filter(({date}) => date <= '2018-06-01')
+        cycleDays: mucusPeak5DaysAfterFhm
+          .filter(({date}) => date <= '2018-06-01')
       })
       expect(status.phases.periOvulatory).to.eql({
         start: { date: '2018-06-02' },
         end: { date: '2018-06-22', time: '18:00' },
-        cycleDays: mucusPeak5DaysAfterFhm.filter(({date}) => {
-          return date > '2018-06-01' && date <= '2018-06-22'
-        })
+        cycleDays: mucusPeak5DaysAfterFhm
+          .filter(({date}) => {
+            return date > '2018-06-01' && date <= '2018-06-22'
+          })
       })
       expect(status.phases.postOvulatory).to.eql({
         start: {
           date: '2018-06-22',
           time: '18:00'
         },
-        cycleDays: mucusPeak5DaysAfterFhm.filter(({date}) => date >= '2018-06-22')
+        cycleDays: mucusPeak5DaysAfterFhm
+          .filter(({date}) => date >= '2018-06-22')
       })
     })
 
     it('with mucus peak 2 days before fhM waits for end of temp eval', () => {
       const status = getSensiplanStatus({
         cycle:  mucusPeakTwoDaysBeforeFhm,
-        previousCycles: [cycleWithTempShift]
+        previousCycles: [cycleWithFhm]
       })
 
       expect(status.temperatureShift).to.be.an('object')
@@ -253,28 +270,31 @@ describe('sympto', () => {
       expect(status.phases.preOvulatory).to.eql({
         start: { date: '2018-06-01' },
         end: { date: '2018-06-04' },
-        cycleDays: mucusPeakTwoDaysBeforeFhm.filter(({date}) => date <= '2018-06-04')
+        cycleDays: mucusPeakTwoDaysBeforeFhm
+          .filter(({date}) => date <= '2018-06-04')
       })
       expect(status.phases.periOvulatory).to.eql({
         start: { date: '2018-06-05' },
         end: { date: '2018-07-03', time: '18:00' },
-        cycleDays: mucusPeakTwoDaysBeforeFhm.filter(({date}) => {
-          return date > '2018-06-04' && date <= '2018-07-03'
-        })
+        cycleDays: mucusPeakTwoDaysBeforeFhm
+          .filter(({date}) => {
+            return date > '2018-06-04' && date <= '2018-07-03'
+          })
       })
       expect(status.phases.postOvulatory).to.eql({
         start: {
           date: '2018-07-03',
           time: '18:00'
         },
-        cycleDays: mucusPeakTwoDaysBeforeFhm.filter(({date}) => date >= '2018-07-03')
+        cycleDays: mucusPeakTwoDaysBeforeFhm
+          .filter(({date}) => date >= '2018-07-03')
       })
     })
 
     it('with mucus peak 5 days before fhM waits for end of temp eval', () => {
       const status = getSensiplanStatus({
         cycle:  fhm5DaysAfterMucusPeak,
-        previousCycles: [cycleWithTempShift]
+        previousCycles: [cycleWithFhm]
       })
 
       expect(status.temperatureShift).to.be.an('object')
@@ -284,21 +304,24 @@ describe('sympto', () => {
       expect(status.phases.preOvulatory).to.eql({
         start: { date: '2018-06-01' },
         end: { date: '2018-06-05' },
-        cycleDays: fhm5DaysAfterMucusPeak.filter(({date}) => date <= '2018-06-05')
+        cycleDays: fhm5DaysAfterMucusPeak
+          .filter(({date}) => date <= '2018-06-05')
       })
       expect(status.phases.periOvulatory).to.eql({
         start: { date: '2018-06-06' },
         end: { date: '2018-06-21', time: '18:00' },
-        cycleDays: fhm5DaysAfterMucusPeak.filter(({date}) => {
-          return date > '2018-06-05' && date <= '2018-06-21'
-        })
+        cycleDays: fhm5DaysAfterMucusPeak
+          .filter(({date}) => {
+            return date > '2018-06-05' && date <= '2018-06-21'
+          })
       })
       expect(status.phases.postOvulatory).to.eql({
         start: {
           date: '2018-06-21',
           time: '18:00'
         },
-        cycleDays: fhm5DaysAfterMucusPeak.filter(({date}) => date >= '2018-06-21')
+        cycleDays: fhm5DaysAfterMucusPeak
+          .filter(({date}) => date >= '2018-06-21')
       })
     })
   })
@@ -306,8 +329,8 @@ describe('sympto', () => {
   describe('applying the minus-8 rule', () => {
     it('shortens the pre-ovu phase if there is a previous <13 fhm', () => {
       const status = getSensiplanStatus({
-        cycle:  cycleWithTempAndMucusShift,
-        previousCycles: [fhmOnDay12, cycleWithTempShift]
+        cycle:  longAndComplicatedCycle,
+        previousCycles: [fhmOnDay12, ...Array(13).fill(fhmOnDay15)]
       })
 
       expect(status.temperatureShift).to.be.an('object')
@@ -317,28 +340,170 @@ describe('sympto', () => {
       expect(status.phases.preOvulatory).to.eql({
         start: { date: '2018-06-01' },
         end: { date: '2018-06-04' },
-        cycleDays: fhm5DaysAfterMucusPeak.filter(({date}) => date <= '2018-06-04')
+        cycleDays: longAndComplicatedCycle
+          .filter(({date}) => date <= '2018-06-04')
       })
       expect(status.phases.periOvulatory).to.eql({
         start: { date: '2018-06-05' },
-        end: { date: '2018-06-17', time: '18:00' },
-        cycleDays: fhm5DaysAfterMucusPeak.filter(({date}) => {
-          return date > '2018-06-04' && date <= '2018-06-17'
-        })
+        end: { date: '2018-06-21', time: '18:00' },
+        cycleDays: longAndComplicatedCycle
+          .filter(({date}) => {
+            return date > '2018-06-04' && date <= '2018-06-21'
+          })
       })
       expect(status.phases.postOvulatory).to.eql({
         start: {
-          date: '2018-06-17',
+          date: '2018-06-21',
           time: '18:00'
         },
-        cycleDays: fhm5DaysAfterMucusPeak.filter(({date}) => date >= '2018-06-17')
+        cycleDays: longAndComplicatedCycle
+          .filter(({date}) => date >= '2018-06-21')
+      })
+    })
+    it('shortens pre-ovu phase with prev <13 fhm even with <12 cycles', () => {
+      const status = getSensiplanStatus({
+        cycle:  longAndComplicatedCycle,
+        previousCycles: Array(11).fill(fhmOnDay12)
+      })
+
+      expect(status.temperatureShift).to.be.an('object')
+      expect(status.mucusShift).to.be.an('object')
+      expect(status.assumeFertility).to.be.false()
+      expect(Object.keys(status.phases).length).to.eql(3)
+      expect(status.phases.preOvulatory).to.eql({
+        start: { date: '2018-06-01' },
+        end: { date: '2018-06-04' },
+        cycleDays: longAndComplicatedCycle
+          .filter(({date}) => date <= '2018-06-04')
+      })
+      expect(status.phases.periOvulatory).to.eql({
+        start: { date: '2018-06-05' },
+        end: { date: '2018-06-21', time: '18:00' },
+        cycleDays: longAndComplicatedCycle
+          .filter(({date}) => {
+            return date > '2018-06-04' && date <= '2018-06-21'
+          })
+      })
+      expect(status.phases.postOvulatory).to.eql({
+        start: {
+          date: '2018-06-21',
+          time: '18:00'
+        },
+        cycleDays: longAndComplicatedCycle
+          .filter(({date}) => date >= '2018-06-21')
+      })
+    })
+    it('shortens the pre-ovu phase if mucus occurs', () => {
+      const status = getSensiplanStatus({
+        cycle: cycleWithEarlyMucus,
+        previousCycles: Array(11).fill(fhmOnDay12)
+      })
+
+      expect(status.assumeFertility).to.be.true()
+      expect(Object.keys(status.phases).length).to.eql(2)
+      expect(status.phases.preOvulatory).to.eql({
+        start: { date: '2018-06-01' },
+        end: { date: '2018-06-01' },
+        cycleDays: cycleWithEarlyMucus
+          .filter(({date}) => date <= '2018-06-01')
+      })
+      expect(status.phases.periOvulatory).to.eql({
+        start: { date: '2018-06-02' },
+        cycleDays: cycleWithEarlyMucus
+          .filter(({date}) => {
+            return date > '2018-06-01'
+          })
+      })
+    })
+    it('lengthens the pre-ovu phase if >= 12 cycles with fhm > 13', () => {
+      const status = getSensiplanStatus({
+        cycle: longAndComplicatedCycle,
+        previousCycles: Array(12).fill(fhmOnDay15)
+      })
+
+      expect(status.assumeFertility).to.be.false()
+      expect(Object.keys(status.phases).length).to.eql(3)
+      expect(status.phases.preOvulatory).to.eql({
+        start: { date: '2018-06-01' },
+        end: { date: '2018-06-07' },
+        cycleDays: longAndComplicatedCycle
+          .filter(({date}) => date <= '2018-06-07')
+      })
+      expect(status.phases.periOvulatory).to.eql({
+        start: { date: '2018-06-08' },
+        end: { date: '2018-06-21', time: '18:00' },
+        cycleDays: longAndComplicatedCycle
+          .filter(({date}) => {
+            return date > '2018-06-07' && date <= '2018-06-21'
+          })
+      })
+      expect(status.phases.postOvulatory).to.eql({
+        start: {
+          date: '2018-06-21',
+          time: '18:00'
+        },
+        cycleDays: longAndComplicatedCycle
+          .filter(({date}) => date >= '2018-06-21')
+      })
+    })
+
+    it('does not lengthen the pre-ovu phase if < 12 cycles', () => {
+      const status = getSensiplanStatus({
+        cycle: longAndComplicatedCycle,
+        previousCycles: Array(11).fill(fhmOnDay15)
+      })
+
+      expect(status.assumeFertility).to.be.false()
+      expect(Object.keys(status.phases).length).to.eql(3)
+      expect(status.phases.preOvulatory).to.eql({
+        start: { date: '2018-06-01' },
+        end: { date: '2018-06-05' },
+        cycleDays: longAndComplicatedCycle
+          .filter(({date}) => date <= '2018-06-05')
+      })
+      expect(status.phases.periOvulatory).to.eql({
+        start: { date: '2018-06-06' },
+        end: { date: '2018-06-21', time: '18:00' },
+        cycleDays: longAndComplicatedCycle
+          .filter(({date}) => {
+            return date > '2018-06-05' && date <= '2018-06-21'
+          })
+      })
+      expect(status.phases.postOvulatory).to.eql({
+        start: {
+          date: '2018-06-21',
+          time: '18:00'
+        },
+        cycleDays: longAndComplicatedCycle
+          .filter(({date}) => date >= '2018-06-21')
+      })
+    })
+
+    it('does not detect any pre-ovu phase if prev cycle had no fhm', () => {
+      const status = getSensiplanStatus({
+        cycle: longAndComplicatedCycle,
+        previousCycles: [...Array(12).fill(fhmOnDay15), cycleWithoutFhm]
+      })
+
+      expect(status.assumeFertility).to.be.false()
+      expect(Object.keys(status.phases).length).to.eql(2)
+      expect(status.phases.periOvulatory).to.eql({
+        start: { date: '2018-06-01' },
+        end: { date: '2018-06-21', time: '18:00' },
+        cycleDays: longAndComplicatedCycle
+          .filter(({date}) => {
+            return date >= '2018-06-01' && date <= '2018-06-21'
+          })
+      })
+      expect(status.phases.postOvulatory).to.eql({
+        start: {
+          date: '2018-06-21',
+          time: '18:00'
+        },
+        cycleDays: longAndComplicatedCycle
+          .filter(({date}) => date >= '2018-06-21')
       })
     })
-    it('shortens the pre-ovu phase if there is a previous <13 fhm with less than 12 cycles')
-    it('shortens the pre-ovu phase if mucus occurs')
-    it('lengthens the pre-ovu phase if >= 12 cycles')
-    it('does not lengthen the pre-ovu phase if < 12 cycles')
-    it('does not lengthen the pre-ovu phase if < 12 cycles')
   })
 
   describe('when args are wrong', () => {