I had this happen to me and found out I had fibroids. I lost so much blood they wanted to do an emergency blood transfusion. I ended up going to an osteopathic doctor in Benbrook who put me on some supplements that stopped my 3 week bleeding within a month bringing it back down to 5 days. My original OBGYN wanted to do a hysterectomy. If you are interested, I can give you the name of the osteopathic doctor. Good luck.