Bleeding

Sydney
I recently started taking Aviane 28 day bc. I started the white pills to get my period on Thursday last week and had the worst cramps and heavy bleeding. I went back to the bc pills on Saturday because of the pain and bleeding. The bleeding still hasn't stopped. I'm going thru super plus tampons every two hours. And the clots are really big. I had one today that was probably 4-5 inches long. Anybody know what I should do? I've been having normal periods for about 5 years now.