According to the symptoms you provided, you might be experiencing hypermenorrhea (heavy and/or prolonged period bleeding). One of the reasons for hypermenorrhea is a hormonal imbalance that leads to missing menstrual periods, during which the inner lining of the uterus thickens more than usual. when the period finally starts, the whole inner lining has to be moved out of the body. So, it will take more time, more clogs and more blood for the period to end. However, this condition can not be confirmed without an examination from a gynecologist.