Birth control pills help keep you from getting pregnant. The pills with only progestin come in 28-day packs. Every pill is active. Each has only progestin, and no estrogen.
Progestin-only pills work by making your mucus too think for the sperm to move through.
How Do I Start Taking Progestin Pills?
You may start taking these pills at any time.
Protection from pregnancy begins after 2 days. If you have sex within the first 48 hours after your first pill, use another birth control method (such as a condom, diaphragm, or sponge). This is called backup birth control.
How Do I Take Them?
You must take the progestin-only pill at the same time every day.
Never miss a day of taking your pills.
When you have 2 packs of pills left, call your health care provider for an appointment to get a refill. The day after you finish a pack of pills you need to start a new pack.
With these pills you may get no periods, bleed a bit on and off through the month, or get your period on the fourth week.
What if I Don’t Take My Pill on Time?
If you don’t take the progestin pill on time, your mucus will start to thin and you could become pregnant.
When you realize you missed your pill, take it as soon as possible. If it is 3 hours or more since it was due, use a backup birth control method for the next 48 hours after taking the late pill. Then take your next pill at the usual time. If you had sex in the last 3 to 5 days, consider asking your health care provider for emergency contraception. If you have any questions or concerns, call your health care provider.
If you vomit after you take a pill, take another pill as soon as possible, and use a backup birth control method for the next 48 hours.
What to Expect When I Stop
You may decide to stop taking birth control pills because you want to get pregnant or you want to change to another birth control method. Here are some things to expect when you stop taking the pill:
You should get your period 4 to 6 weeks after you take your last pill. If you do not get your period in 8 weeks, call your doctor.
Your period may be heavier or lighter than usual.
You may have mild spotting of blood before you get your first period.
You might become pregnant right away.
When to Use a Backup Method
Use a backup method of birth control, such as a condom, diaphragm, or sponge if:
You take a pill 3 hours or more after it was due.
You miss one or more pills.
You are sick, throwing up, or have loose stools (diarrhea). Even if you take your pill, your body may not absorb it. Use a backup method of birth control, and call your health care provider.
You are taking another medicine that may keep the pill from working. Tell your doctor or pharmacist if you take any other medicines, such as antibiotics, seizure medicine, medicine to treat HIV, or St. John’s wort. Find out if what you take will interfere with the pill working.
When to Call the Doctor
Call your doctor if:
You have swelling in your leg
You have leg pain
Your leg feels warm to the touch or changes in skin color
Susan Storck, MD, FACOG, Chief, Eastside Department of Obstetrics and Gynecology, Group Health Cooperative of Puget Sound, Bellevue, Washington; Clinical Teaching Faculty, Department of Obstetrics and Gynecology, University of Washington School of Medicine. Also reviewed by A.D.A.M. Health Solutions, Ebix, Inc., Editorial Team: David Zieve, MD, MHA, David R. Eltz, Stephanie Slon, and Nissi Wang.