Why is menstruation not over yet?

General normal female menstrual days should be between 3-7 days. More than 7 days of menstruation did not stop, may be caused by gynecological diseases, may also be caused by pregnancy or endocrine disorders. It is recommended that patients see a doctor in time, improve color ultrasound, leucorrhea routine, blood HCG and other examinations, clear the cause of treatment.