BC period? (Is this normal?)

So I'm on my first period since I started taking birth control pills on August 23rd. It started yesterday and I've had really bad cramps but hardly any bleeding. There's a lot of brown/pink clotting and mucus but never any bright red blood like I used to always have. My periods were a week long, heavy bleeding during first two days, and bad cramps. I have not been having sex, so there's no way I'm pregnant. Is it normal for my period to have become so light like this?