Im regular 28 days.I always take my birth control pills but I already wanted to stop taking them. I started my period around August 12th Friday and I stopped taking the pill on Wednesday August 24. I have a period tracker app and it tells me when you're going to ovulate which is on the 26th of august . Today I felt minor cramp and my period which doesn't start until 13 days ...so I don't know if it ovulation or because I stopped taking the pill.