Re: Why do we still get our period while on birth control?
The pill supresses your natural menstruation, and all you are experiencing while on the pill is a withdrawal bleed that is brought on by the sudden drop in hormone levels during your placebo week. I know this is very confusing, and it's unfortunate that the doctors don't take more time to explain this to you.
During a natural menstrual period, the ovaries are signalled to shed the lining of the uterus in preparation for ovulation to occur between 10-18 days later (depending on the woman). This is all a completely natural thing that is how women are supposed to menstruate.
For a woman who is on the pill, there is never a natural menstrual period. Rather, the pill tricks the body into thinking it's already pregnant and therefore should not be ovulating. The 7-day placebo break that is at the end of the pill pack is there to help the woman to shed her lining, although it's an artificial shedding that is brought on simply because the hormone levels in the pill are suddenly dropped in that placebo week. It has nothing to do with the body's natural tendency toward a menstrual bleed.
Breakthrough bleeding and spotting can occur when there is not a high enough estrogen level in the pill that the woman is taking. It happens because the level of hormone in the body is not enough, and therefore causes the fake bleed to occur.
I hope that helps to explain this a little better. Your doctor really should have explained all of this to you before giving you the pill, but unfortunately, they just don't care enough about their patients to ensure they are fully informed about their meds before prescribing them.