Women's Health Community

Dear An: If the pregnancy test is negative then the next most common cause of a missed period is not having ovulated that cycle. In a normal cycle, estrogen is produced all month. Estrogen is responsible for building up the lining of your uterus so you have something to shed each month.

In a normal cycle, progesterone production increases following ovulation. Progesterone "stabilizes" the uterine lining in preparation for a possible implantation of a new pregnancy. If you are not pregnant that month the levels of estrogen and progesterone fall, triggering the release of the uterine lining—your period.

So, if you do not ovulate, the estrogen build up of the lining continues, but without the usual ovulation associated progesterone. Thus, the hormone levels don't decline, and the lining stays up inside the uterus—your missed period. Alternatively, the built up lining can begin to shed on its own creating erratic bleeding patterns which are usually "too-light" or super heavy and prolonged. This is similar to what you have been experiencing.

If one has been several months without a period, a gynecologist may give you some progesterone in a pill form (eg Provera 10 mg for 5 days). Within 48-72 hours after stopping the progesterone your "progesterone blood level" will fall, triggering the release of the lining that has been building up. Many women report that these periods are very heavy-- as though several months of lining are shed. I suspect this was the medication that your GYN prescribed.

Causes for not ovulating are many: low thyroid, pituitary problems, ovarian cysts, physical stressors (eg sudden increases in exercise, crash dieting, lack of sleep), emotional stressors (problems with boyfriends/girlfriends, finances), increased body weight, anorexia, rotating shifts at work, etc. It sounds like your two blood tests for low thyroid and pituitary problems (blood prolactin level) were both normal. Thus any missed ovulations may be from one of these other reasons.

So, what to do about the current bleeding pattern? I would urge you to return to your GYN or clinic. A short course of hormones can get the bleeding to stop. If Provera is given you may have another flow but it will be an orderly shed of the lining that will stop in a reasonable time. You could choose to self monitor after Provera pills and see if your cycle straightens out on its own. If it does not your GYN might suggest birth control pills for three months just to get regular "periods" and to keep the lining from getting too built up.

Yours,
Jane