My last months calendar has changed and now says we didn't even try the right days?? I don't understand why? Last month (September 2015) it told us the three best days were the 16th, 17th, and 18th. My AF was due 10/2 and came today 10/8. Now looking back to explain to my husband about good days to try and the days have changed? Can someone please explain? How are we even supposed to feel like were doing the right times?