Constant Menstruation

I have my period the first week and the last two weeks of every month. The bleeding is a little heavy tasks. The cramps are unbearable to none existent. It's like that with and with out birth control. What could be causing this?

Same problem when I asked this question once a woman said it was a hormonal imbalance. She said she was going to the doctor and he put a pill 9 days and five days later, her period stopped. Me and my mother said we were going to count how many days my last period and then tell me doctor.