I'm worried!


So in the middle of july I was taking birth control and the pills were giving me really bad cramps, I had finished the pack when my sister gave me one of her packs of birth control pills they werent giving me horrible cramps as the 1st pack. On the last week of the 1st pack and the last pill I had started my period it was heavy with bad cramps. After I was done with my period a few days later I started spotting for only a while, I had my started sotting this month in august on the 16 and on the 17 I started my period and ended on the 21. On the 24 agian I started spotting and today is the 30 and I started bleeding as if I was going to start my period agian!!! I am super worried...I tell y doctor but she says it's normal and also my boobs (nipples) have been hurting since this all started....

Is this even normal, bc I'm freaking out its stressing me out...idk what doo.