I usually always have a very regular menstural cycle. Always starts between the 14-17 of the month. I have not had sex since November, and it was with a condom and while I was on birth control. I quit taking birth control in janurary and my cycles have been normal. I've had a period every month, but this one isn't showing up. I do have a history of ovarian cysts but no irregularities in mensturating. For reference, I'm 16 and began mensturating when I was 11. Thank you all!