What does it mean when you stop having your period while on the pill? I've been on the pill for five years, and for about three years I haven't had a period. My doctors have all agreed that this is possible when on the pill. I'm worried that it is not safe. Could this affect my fertility?

B.A.

Most birth control pills are a combination of estrogen and progesterone. The contraceptive benefit comes predominantly from the progesterone. The estrogen is only present to help control the menstrual bleeding. It was thought that women would feel uncomfortable if they had no menses or breakthrough bleeding and spotting. So, estrogen was added.

Once we learned more about pill formulations, and as newer progestogens became available, it became obvious that the dose of estrogen could be lowered. Lowering the pill's estrogen content also meant that many of the pill's side effects could be avoided. Unfortunately, this has meant that some women may stop having periods.

The good news is that skipping a period while on the pill presents absolutely no health risk and has no effect on your future fertility. There is no reason to get off the pill or even take a "pill-break" to "fix" things back to normal. Just enjoy the menses-free months.