Hormonal birth control use
Once you start using birth control pills, your periods are regulated by the hormones in the pills. Your periods may become lighter or less frequent, or you may not have periods at all.
It is still possible to become pregnant when you are using birth control pills, especially if:
- You skip one or more pills. Your highest risk occurs if you miss pills early in the cycle or pack, or if you start your next pack a day or two late.
- Your health professional changes your birth control pill prescription, and the new pills have a different dosage of estrogen and progesterone.
- You are also using daily, long-term seizure medicines, such as phenytoin (Dilantin), phenobarbital, or carbamazepine (Tegretol); or daily, long-term antibiotics, such as rifampin, ampicillin, or tetracycline.
Do a home pregnancy test if you think you might be pregnant.
The changes caused by the use of progesterone alone, such as Depo-Provera, wImplanon, or in the mini-pill, vary considerably from woman to woman. You may have normal periods, bleeding between periods, irregular bleeding, or no periods at all.
When you start using a new hormonal birth control method, ask your health professional what you can expect your periods to be like. If your pattern is very different from what you were expecting or if there is a sudden change in the timing or severity of bleeding, contact your health professional.
| Author: | Jan Nissl, RN, BS | Last Updated: July 5, 2007 |
| Medical Review: | Kathleen Romito, MD - Family Medicine Kirtly Jones, MD - Obstetrics and Gynecology | |
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