diff --git a/lib/cycle.js b/lib/cycle.js
index dcac869..a5bd7d3 100644
--- a/lib/cycle.js
+++ b/lib/cycle.js
@@ -101,21 +101,23 @@ export default function config(opts) {
     }
   }
 
-  function getMensesDaysAfter(cycleDay) {
-    const bleedingDays = bleedingDaysSortedByDate.filter(d => {
-      return !d.bleeding.exclude
+  function getMensesDaysRightAfter(cycleDay) {
+    const bleedingDays = bleedingDaysSortedByDate
+      .filter(d => {
+        return !d.bleeding.exclude
+      })
+      .reverse()
+    const firstFollowingBleedingDayIndex = bleedingDays.findIndex(day => {
+      return day.date > cycleDay.date
     })
-    const startIndex = bleedingDays.findIndex(day => {
-      return day.date === cycleDay.date
-    })
-    return recurse(cycleDay, startIndex, [])
+    return recurse(cycleDay, firstFollowingBleedingDayIndex, [])
 
-    function recurse(day, i, mensesDays) {
-      if (i === 0) return mensesDays
-      const next = bleedingDays[i - 1]
+    function recurse(day, nextIndex, mensesDays) {
+      const next = bleedingDays[nextIndex]
+      if (!next) return mensesDays
       if (!isWithinThreshold(day, next)) return mensesDays
       mensesDays.unshift(next)
-      return recurse(next, i - 1, mensesDays)
+      return recurse(next, nextIndex + 1, mensesDays)
     }
 
     function isWithinThreshold(cycleDay, nextCycleDay) {
@@ -174,6 +176,37 @@ export default function config(opts) {
     return predictedMenses
   }
 
+
+  // TODO this also needs a test
+  function maybeSetNewCycleStart(oldCycleDay, newValue) {
+    // if a bleeding value is deleted, we need to check if
+    // there are any following bleeding days and if the
+    // next one of them is now a cycle start
+
+    // in order to get the menses days, the cycle day in question still
+    // has to have a bleeding value, so we get those days first and only
+    // then update the cycle day
+    const mensesDaysAfter = getMensesDaysRightAfter(oldCycleDay)
+    oldCycleDay.bleeding = newValue
+    oldCycleDay.isCycleStart = false
+
+    if (!mensesDaysAfter.length) return
+
+    const nextOne = mensesDaysAfter[mensesDaysAfter.length - 1]
+    if (isMensesStart(nextOne)) {
+      nextOne.isCycleStart = true
+    }
+  }
+
+  function maybeClearOldCycleStartsInThisMenses(cycleDay) {
+    // if we have a new bleeding day, we need to clear the
+    // menses start marker from all following days of this
+    // menses that may have been marked as start before
+    const mensesDaysAfter = getMensesDaysRightAfter(cycleDay)
+    mensesDaysAfter.forEach(day => day.isCycleStart = false)
+  }
+
+
   return {
     getCycleDayNumber,
     getCycleForDay,
@@ -182,6 +215,8 @@ export default function config(opts) {
     getAllCycleLengths,
     getPredictedMenses,
     isMensesStart,
-    getMensesDaysAfter
+    getMensesDaysRightAfter,
+    maybeSetNewCycleStart,
+    maybeClearOldCycleStartsInThisMenses
   }
 }
\ No newline at end of file
diff --git a/test/cycle.spec.js b/test/cycle.spec.js
index 8508748..af07e6d 100644
--- a/test/cycle.spec.js
+++ b/test/cycle.spec.js
@@ -904,7 +904,7 @@ describe('isMensesStart', () => {
   })
 })
 
-describe('getMensesDaysAfter', () => {
+describe('getMensesDaysRightAfter', () => {
   it('works for simple menses start', () => {
     const cycleDaysSortedByDate = [
       {
@@ -927,11 +927,11 @@ describe('getMensesDaysAfter', () => {
       }
     ]
 
-    const { getMensesDaysAfter } = cycleModule({
+    const { getMensesDaysRightAfter } = cycleModule({
       cycleDaysSortedByDate,
       bleedingDaysSortedByDate: cycleDaysSortedByDate.filter(d => d.bleeding)
     })
-    const days = getMensesDaysAfter(cycleDaysSortedByDate[3])
+    const days = getMensesDaysRightAfter(cycleDaysSortedByDate[3])
     expect(days).to.eql([
       {
         date: '2018-05-03',
@@ -944,6 +944,50 @@ describe('getMensesDaysAfter', () => {
     ])
   })
 
+  it('works when the day is not a bleeding day', () => {
+    const cycleDaysSortedByDate = [
+      {
+        date: '2018-05-04',
+      },
+      {
+        date: '2018-05-03',
+        bleeding: { value: 1 }
+      },
+      {
+        date: '2018-05-02',
+        bleeding: { value: 1 }
+      },
+      {
+        date: '2018-05-01',
+        bleeding: { value: 1 }
+      },
+      {
+        date: '2018-04-30',
+        bleeding: null
+      }
+    ]
+
+    const { getMensesDaysRightAfter } = cycleModule({
+      cycleDaysSortedByDate,
+      bleedingDaysSortedByDate: cycleDaysSortedByDate.filter(d => d.bleeding)
+    })
+    const days = getMensesDaysRightAfter(cycleDaysSortedByDate[4])
+    expect(days).to.eql([
+      {
+        date: '2018-05-03',
+        bleeding: { value: 1 }
+      },
+      {
+        date: '2018-05-02',
+        bleeding: { value: 1 }
+      },
+      {
+        date: '2018-05-01',
+        bleeding: { value: 1 }
+      }
+    ])
+  })
+
   it('ignores excluded values', () => {
     const cycleDaysSortedByDate = [
       {
@@ -966,11 +1010,11 @@ describe('getMensesDaysAfter', () => {
       }
     ]
 
-    const { getMensesDaysAfter } = cycleModule({
+    const { getMensesDaysRightAfter } = cycleModule({
       cycleDaysSortedByDate,
       bleedingDaysSortedByDate: cycleDaysSortedByDate.filter(d => d.bleeding)
     })
-    const days = getMensesDaysAfter(cycleDaysSortedByDate[3])
+    const days = getMensesDaysRightAfter(cycleDaysSortedByDate[3])
     expect(days).to.eql([
       {
         date: '2018-05-03',
@@ -999,11 +1043,11 @@ describe('getMensesDaysAfter', () => {
       }
     ]
 
-    const { getMensesDaysAfter } = cycleModule({
+    const { getMensesDaysRightAfter } = cycleModule({
       cycleDaysSortedByDate,
       bleedingDaysSortedByDate: cycleDaysSortedByDate.filter(d => d.bleeding)
     })
-    const days = getMensesDaysAfter(cycleDaysSortedByDate[3])
+    const days = getMensesDaysRightAfter(cycleDaysSortedByDate[3])
     expect(days).to.eql([])
   })
 
@@ -1028,11 +1072,11 @@ describe('getMensesDaysAfter', () => {
       }
     ]
 
-    const { getMensesDaysAfter } = cycleModule({
+    const { getMensesDaysRightAfter } = cycleModule({
       cycleDaysSortedByDate,
       bleedingDaysSortedByDate: cycleDaysSortedByDate.filter(d => d.bleeding)
     })
-    const days = getMensesDaysAfter(cycleDaysSortedByDate[3])
+    const days = getMensesDaysRightAfter(cycleDaysSortedByDate[3])
     expect(days).to.eql([])
   })
 
@@ -1058,11 +1102,11 @@ describe('getMensesDaysAfter', () => {
       }
     ]
 
-    const { getMensesDaysAfter } = cycleModule({
+    const { getMensesDaysRightAfter } = cycleModule({
       cycleDaysSortedByDate,
       bleedingDaysSortedByDate: cycleDaysSortedByDate.filter(d => d.bleeding)
     })
-    const days = getMensesDaysAfter(cycleDaysSortedByDate[3])
+    const days = getMensesDaysRightAfter(cycleDaysSortedByDate[3])
     expect(days).to.eql([
       {
         date: '2018-05-05',
@@ -1090,11 +1134,11 @@ describe('getMensesDaysAfter', () => {
         }
       }]
 
-      const getMensesDaysAfter = cycleModule({
+      const getMensesDaysRightAfter = cycleModule({
         bleedingDaysSortedByDate: bleedingDays,
         maxBreakInBleeding
-      }).getMensesDaysAfter
-      const result = getMensesDaysAfter(bleedingDays[1])
+      }).getMensesDaysRightAfter
+      const result = getMensesDaysRightAfter(bleedingDays[1])
       expect(result).to.eql([bleedingDays[0]])
     })
 
@@ -1111,11 +1155,11 @@ describe('getMensesDaysAfter', () => {
         }
       }]
 
-      const getMensesDaysAfter = cycleModule({
+      const getMensesDaysRightAfter = cycleModule({
         bleedingDaysSortedByDate: bleedingDays,
         maxBreakInBleeding
-      }).getMensesDaysAfter
-      const result = getMensesDaysAfter(bleedingDays[1])
+      }).getMensesDaysRightAfter
+      const result = getMensesDaysRightAfter(bleedingDays[1])
       expect(result).to.eql([])
     })
   })