I just cant afford to gain weight after all the work i did to los...

It really can "make you gain weight," but not very much--for me it's never been more than 6 or 7 pounds. It's the same as with any hormonal birth control: the hormones interact with other hormones in your body, including those that control your basal metabolism (how quickly you burn calories) and those that control your energy levels. They can also make you retain water. Especially when I first started taking the pill, I noticed a small drop in my metabolism and an increase in my appetite, but if you're already eating healthfully and exercising, I don't think it'll give you too much trouble. Just try to keep going with any diet & exercise plan you're already doing, and you should be fine. Aviane is nice as far as birth control pills go--its side effects seem to be the least severe, at least for me.