What to expect from going off of the birth control pill?

I'm on Ocella right now (generic version of Yasmin) and only went on it for my skin, so getting pregnant isn't an issue. But I've been on it for a few years and am 19 now, so hopefully the skin issue won't be as prevalent anymore, and have gained about 20 pounds from the pill, and it's been extremely difficult for me to lose weight because of it (apparently it's much harder to lose weight while you're on the pill, and I'm living proof). Anyway, I want to go off the pill so I can get back on track for losing weight. What can I expect if I go off the pill as far as side effects go? Thanks.