heavy bleeding after end of period that resulted in a d&

I hope someone can help me. I have always had normal periods. I am 30 years old and have one child. I was Preg about 3 months ago however had to have a D&C because at 10wks the baby had miscarried. The period after the first D&C was extremely heavy-which was expected. The second period came 28 days from that and also was very heavy-more than usual but then subsided. However, when the period ended I started bleeding so heavily to the point that I had to go to the ER. I had loss half my blood supply I was bleeding so much. I had to have another D&C and this stopped the bleeding. Again, I have always had normal periods, I always got preg on the first try as well. The docs told me that they think I didn't ovulate for a month which caused the lining of my uterus to become thick and that' s why I bled so much passing so many large clots. THey now put me on birth control for a couple of months thinking that the hormones will regulate my body to prevent me from not ovulating again. We really want to try for another child but obviously we can't until I'm healthy again. Has anyone ever heard of what happened to me? I just don't trust what the dr's have said.