Start birth control on first day of period

Who Can Take Them

As long as your doctor is sure that you’re not already pregnant, you usually can get on the pill at any time, at any age. If you’re nearing menopause, ask your doctor if it might be better to take a “minipill,” which has one hormone instead of the usual two, and in lesser amounts.

The pill may not be right for you if you:

• Have high blood pressure that isn’t well controlled
• Are over 35 and smoke
• Have a history of stroke, heart disease, circulation problems, or breast cancer
• Started breastfeeding within the past month
• Have migraine headaches with aura
• Have diabetes-related complications like nephropathy, retinopathy, or neuropathy
• Recently had surgery
• Have liver disease
• Have unexplained uterine bleeding

Learn more about the pill and other birth control choices that are right for you.

How to Get Started

Before your doctor writes a prescription, they'll take your blood pressure and check for any sexually transmitted diseases if you’ve had sex before. You may or may not need a full gynecological exam.

You have several ways to get on the pill:

First-day start. Take your first pill the day you get your period. Pregnancy protection kicks in right away, so you won’t need a backup contraceptive.

Quick start. You take the first pill in your pack right away. This is an option if your doctor confirmed that you’re not already pregnant (although a pregnancy test may not produce a positive result early in a pregnancy). The hormones in the pills need time to build up in your body. So you’ll need back-up contraception, like a condom, for 7 days. This method is generally not recommended. 

Sunday start. Many pill packs are arranged to start on this day. You take your first pill on the first Sunday after your menstruation starts. Use a second birth control method for 7 days if you have sex.

Types of Pill Packs

Most women get their pills in packets of 21 or 28. You also can get extended packs of 91 pills or 365 pills. With those types of pills, your periods may get more infrequent or bleed much less.

21-day pills. You take one pill at the same time each day for 21 days, then wait 7 days before starting a new pack. You will have your period during those 7 days.

28-day pills. You take one pill at the same time each day for 28 days. The first 21-26 pills (depending on the brand) have the hormones estrogen and progestin. The rest are usually inactive, or dummy, pills. You will menstruate during the last 4-7 days.

91-day pills. You take one pill at the same time each day for 84 days. The last 7 pills have estrogen only or will be inactive. You will have your period during the last 7 days.

365-day pills. You take one pill at the same time each day for a full year. Your periods may get lighter or stop altogether.

How to Take the Pill

Take your pill every day at the same time. This is especially important if you’re on the progestin-only minipill, which has a smaller margin for error than regular pills with both estrogen and progestin. It may help to set an alarm on your phone or post a calendar on your fridge as a reminder. When you finish a packet (including any dummy pills), take the first pill in a new packet the next day.

Some medications, including the antibiotic rifampin and the herb St. Johns wort, can interact with birth control pills. So use a back-up contraceptive.

Missed Doses

Birth control pills work extremely well to prevent unintended pregnancies. But that depends on sticking to your pill schedule to keep your hormone levels where they need to be to block conception.

If it’s been less than 48 hours since the time of your last pill:

• Take the late or skipped dose right away.
• Take the rest of the pills in your pack on your regular schedule, even if you must take two pills on the same day.

If it’s been more than 48 hours since your last dose:

• Take the most recent missed pill as soon as possible and throw out any others that you missed.
• Take the rest of the pills in your pack on your regular schedule, even if you must take two pills together to get back on track.
• Use backup contraception (like condoms) or don’t have sex until you’ve taken pills containing hormones for 7 straight days.
• If you skipped the last week of pills with hormones in your pack (days 15-21 of a 28-day pack):
  • Finish the pills containing hormones, throw away the hormone-free pills, and start a new pack the next day.
  • If you can’t start the new pack right away, use backup contraception or don’t have sex until you take pills containing hormones for 7 days in a row.

If you missed the pills during the first week of your pack and you had unprotected sex during the 5 days before, check with your doctor about the need for emergency contraception. Read more on what to do if you forget to take your birth control pill.

How to Quit

You can get off birth control pills any time you want, although stopping at the end of a pill pack is recommended. You may notice some bleeding or spotting, and your periods may be irregular for a while. You will probably start ovulating again within 2 weeks so you can try for a baby. Get more information on how to safely stop using birth control.