I need some help in regards to birth control...first time on it so just want to know of othe women's exp w/ it?

So I had my period for 3 weeks straight after not having it for a while and I decided to go on birth control since my doctor told me it would regulate my period. I started the pills and to my surprise my period lightened and over the course of 5 days it was gone....only spotting but barely noticeable. However, its been a week since I started the pills and now I got my period again. The doctor I see said that its normal to spot in between but this isnt spotting, its my actual period and she also said it could take up to 3 months to fully regulate. My question is if any of you women have had a similar situation? A doctor can say this and that but I would like to know of actual experiences just to get a better idea. Also, I looked online for the type of pill I got which is Ortho Try Cyclen Lo and found reviews that many women's breast grew a bit more, but I was wondering if it could happen to your butt....because although its only been about 10 days that ive been on the pill I can tell a difference in size of my butt...a lil bigger...or could I be gaining weight?