After stream of people 5 months menstruation is normal, why this month can defer

Menstruation delay is considered to be caused by endocrine disorders, and daily diet, rest time, emotional changes, mental state and other factors, there may be endometriosis caused, do not rule out the possibility of polycystic ovary syndrome; should go to the regular hospital obstetrics and gynecology department to do B ultrasound, sex hormone six examinations.