I've been on the pill for about four years (there was one month, about two years ago that I missed completely). I take it everyday, but not always at the same time of day. I am sexually active, but have been using condoms that, as far as I know, haven't broken. When I first started taking the pill my periods were very routine every month, then they started coming every other month. And now I haven't had one in about two months. I still get the occasional cramps that feel like period cramps. Can this happen when you're on the pill, or should I be worried about possible pregnancy?