Birth Control

Okay so I was taking the pill (only for about 4 months- I've been off for over a year now). Me and my BF are very active but we use protection every time.. I was taking the pill and gained roughly 40-50 pounds out of no where! After over a year, I'm finally getting back down to my weight before BC. His mom wants me back on birth control it seems like and I don't really want to try anything else. I don't want the shot and I don't want to gain any more weight. I'm finally becoming happy with my body again. Any one else feel this way? What font of birth control are you using? Anything that I can use that WONT make me gain so much weight? Thanks ladies.