Was wondering..

Shauna • TTC after 2 miscarriages & with PCOS💗

This might be a stupid question but how do you know when your next period is goin to show up? I have very irregular periods. Actually the only time it was regular was when I was taking bc. And I had to take Provera to get my last period to come. It is usually 4 weeks after your last one? I know it can be 28, 29, or 30 days. I was curious what most of yalls are....