I haven't had my period for four months and i am not pregnant. what should i do?

Common problem : Irregular periods are one of the most common problems obgyns treat. If this is one time problem it usually resolves on its own. If this is a recurring problem you should be evaluated. Infections & hormonal changes can cause spotting. If there is a concern for pregnancy then redo a home pregnancy test . There are many options available to help regulate the menstrual cycle. Schedule a visit.

Many possibilities: It could be hormonal, that is, an imbalance if estrogen and progesterone. Most common would be extremes of weight (thin or heavy). It could be your thyroid or pituitary. If no period for 6 months, see your doctor as some conditions such as pcos can put you at increased risk for uterine cancer if left untreated. Best of luck.

See your doc: It is important for a women to have a period about every 10 - 12 weeks (if not pregnant of course). If you don't, the lining of your uterus can get too thick and you can bleed excessively when you do finally have your period. Also, it can start to undergo pre-cancerous changes if it gets too thick. See your doc to find out why you haven't had a period and to get one to come.

Possible causes of: Absence of menses include hormonal imbalance, medications including contraceptive pills, ovarian cyst, stress, medical illness etc http://www.Healthline.Com/health/secondary-amenorrhea?Toptoctest=expand.