Community post

How long your period lasts has no bearing on how long your cycles are. Your cycle length is determined by when you ovulate & the length of your lp.

Your cycle starts the first day of your period and ends the day before your next period. So count how many days in between and that's your cycle length. Number of days of your period is irrelevant.

You can get an free app for your phone called woman log or period tracker (there are a few of them) and put details in, first and last day of period etc. As the months go by it works out /you can see how long your cycle is and where your most fertile time is estimated to be. Then you could use ovulation sticks etc to work out where you ovulate. (the default is 28 days but add the months go by you can work out if cycle longer and manually change it etc.
(I use womanlog)