Hello,
From your symptoms, it can be due to metrorrhagia even. Various factors causing it are endometriosis,ectopic pregnancy,hormone imbalance,endometrial hyperplasia,polyps,use of IUD’s and depo shots, sexually transmitted diseases,PCOS and benign and malignant pathologies of the uterus.
If you have prolonged bleeding then it is advisable to consult a gynecologist.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.
Have they checked for fibroids? I would go to your dr & ask what your options are. but it sounds like you will either need to go on a form of birth control to control the heavy bleeding OR you might need to look at other options with your dr such as a hysterectomy, Their are many things it could be.. but I encourage you to be seen as soon as possible because when you bleed heavily its very easy for your body to become anemic or worse. I almost lost my mother because she was bleeding heavy & didn't realize how much blood she lost.