Abnormal bleeding

My periods from May Until now have been 1 week early to 1 week late. My Period for December was extremely heavy and I was bleeding from the beginning of December until January 9th off and on. I have Really bad cramping, I've been sick to my stomach and have even thrown up a few times. The pain gets worse as well as the bleeding during and after sex. The cramping also gets worse when I have a full bladder or have to have a BM. I have had my kidney, liver and gallbladder levels checked, as well as my thyroid and all was normal. Also had a pregnancy test and an exam to check for pulps. All was normal. I just had an ultra sound done today and should know the results in a day or so. My doctor just put me on a medication called Provera to help with my bleeding. Which has helped but i still have very light spotting from time to time.

My history: 3 c sections along with a tubal on my last c section. and 1 DNC. I have a history of bladder, kidney and UTI infections. I also have a Rare disease called Osteogenesis Imperfecta, which is a brital bone disease but also effects other things.

This morning I woke up with very bad cramping and when I went to the bathroom, I had A LOT of black/or very dark brown discharge, it was almost period flow ( thats how heavy it was ) and my stomach is still cramping bad and the discharge is still there.