Period won't stop.

Hey! I had my daughter 8 months ago. I got birth control in December & instantly started bleeding. The bleeding & pain wouldn't stop & it eventually moved down to my cervix so I got it removed in February. It's now May & I still am bleeding going through about 18 tampons every 3 to 4 days. I've seen my ob & he said he doesn't know. He gave me provera but that didn't stop my bleeding either. Any ideas? This is annoying.