I had the same problem. 2 yrs ago I started to bleed & clot very heavy for a long time...about 25 days at a time. After an MRI & ultrasound came back neg, my gyn sent me to hemotologist (blood specialist) & found out I had a thyroid disorder. I am on medication now & for the first time in 2 years I had a normal period (5 days) Maybe, you can ask your dr if she/he could check your thyroid, ya never know. Good Luck
I would say anything to do with bleeding that is not normal for you to go and see a doctor and you say you have been bleeding for a month thats not good !! try not to worry but in the meantime book an appointment with your doctor !!