Does the 28 days cycle start on the day you START your period or the LAST day of your period? Just wondering because I'm trying to figure out what week would be best to go to camp so I can avoid it.
cylcle starts the first day of your period. you can work this out due to the pill comming in 21 day packs which you start taking seven days after you start your period
So then, your have the greatest change or are most fertile 12-15 days after the start of your period?
Your cycle starts on the first day of your period.