What happened to two periods a month?

Menstruation twice a month, if the beginning and end of the month to each menstrual period is also normal, may be menstrual cycle ahead of schedule. As long as the advance, there is a certain rule, or is 3 to 7 days in advance are normal. But if the menstrual advance time is too much or the time is not regular, it belongs to menstruation is not adjusted. Menstruation twice a month may and take contraceptives, endocrine disorders, gynecological diseases and so on are related. Need to do b-ultrasound in a timely manner, combined with sex hormone examination to determine. If caused by endocrine disorders, to the cause of conditioning. If caused by gynecological inflammation, can be timely anti-inflammatory treatment. Taking contraceptives may also cause menstruation in advance, belongs to the side effects caused by drugs, can return to normal after stopping.