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Do Birth Control Pills Affect Pregnancy Test Results?

You can get an accurate pregnancy test result even when you’re on birth control pills. The active ingredients in your pills do not affect the specific hormone these tests measure. It’s important to take your pills exactly as prescribed to prevent pregnancy effectively. If you do become pregnant, you should stop taking your pills.

How Pregnancy Tests Work

Pregnancy tests measure the amount of a hormone called human chorionic gonadotropin (hCG) in your urine or blood. After an embryo attaches to the uterine lining, the placenta starts producing hCG at a rapid rate. This hormonal surge is what causes many of the symptoms associated with early pregnancy.

You can either use an at-home pregnancy test that requires urinating on a sensor or you can get your blood drawn for a pregnancy test at your local healthcare provider’s office. Both tests measure the same hormone. If they detect hCG, you’ll receive a positive test result.

At-home pregnancy tests are almost 99% accurate. You can take one after the first day of your missed period, although some tests are more sensitive and can be taken earlier. If your test results are negative but you’re still experiencing pregnancy symptoms such as a missed period, breast tenderness, nausea, and fatigue, you might want to take another test in about a week or schedule a blood test with your medical provider.

Birth Control Hormones and hCG

Most birth control pills contain either a combination of estrogen and progestin or only progestin. These hormones keep you from getting pregnant by preventing the ovaries from releasing eggs and/or keeping the sperm from fertilizing an egg. Estrogen and progestin will not affect hCG, however. This means the presence of birth control pill hormones in your body will not alter your pregnancy test results. The test will still be able to record the accurate amount of hCG in your blood or urine.

While birth control pills and most over-the-counter and prescription medications don’t affect pregnancy tests, a few medications might produce false-positive results. If a medicine contains hCG as an active ingredient, the test results might show you’re pregnant even when you’re not. Infertility medications, for example, often contain hCG as an active ingredient. If you take any medications with hCG and think you might be pregnant, schedule a test with your medical provider rather than taking an at-home pregnancy test.

Can I Get Pregnant on Birth Control?

Despite being up to 99% effective when used correctly, there’s still a chance you can get pregnant while taking birth control pills. On average, about five to nine out of 100 women end up getting pregnant on the pill because they don’t use it correctly. If you want the best protection against pregnancy, it’s important to take your pill at the same time every day and always use a backup method of birth control, such as condoms, if you miss a dose or take your pill late.

If you have trouble sticking to a schedule and taking your pill on time, you can try other types of contraceptives. For example, you only need to remember to replace the birth control patch once a week and the vaginal ring once a month. Long-lasting forms of contraception, such as birth control implants and intrauterine devices (IUDs), protect against pregnancy for several years at a time. These methods might provide you with better protection if you struggle to take birth control pills as directed.

What to Do if You Get Pregnant While Taking the Pill

If you’ve been taking birth control and you find out you’re pregnant, stop taking your pills. You don’t need to worry about any negative effects from continuing to take the pill before you realized you were expecting, however. Scientists haven’t found a link between taking the birth control pill in early pregnancy and the development of birth defects.

There is, however, a slightly increased risk for ectopic pregnancy if you have been taking the mini pill (progestin-only pill) when you become pregnant. This type of pregnancy, which occurs when a fertilized egg implants outside the uterus, is not viable and can have serious health consequences. If you’re taking the mini pill and think you might be pregnant, make an appointment with your healthcare provider to rule out this possibility.

Can Other Forms of Birth Control Affect Pregnancy?

It’s easy to stop taking the pill or to remove a birth control patch or vaginal ring if you become pregnant. Other forms of hormonal birth control aren’t as easy to reverse.

Although they’re some of the most effective forms of birth control, intrauterine devices (IUDs) and the birth control shot (also known as Depo-Provera) offer long-lasting birth control that you can’t stop using immediately if you find out you’re pregnant.

Women who get pregnant with an IUD should schedule an appointment with their medical provider to have it removed as soon as possible. There’s a chance the pregnancy could be ectopic since normal intrauterine pregnancies are unlikely to occur while using an IUD.

Studies have also found that if an IUD is left in place during pregnancy, there is an increased risk of:

  • Miscarriage.
  • Preterm birth.
  • Chorioamnionitis (infection of the amniotic sac and fluid before delivery).

Removing an IUD improves pregnancy outcomes, but still comes with a risk of pregnancy complications.

The birth control shot provides about three months of pregnancy protection. As with IUDs, the low risk for intrauterine pregnancies means that if one does occur, it could be an ectopic pregnancy.

Never use the birth control shot if you think you might be pregnant. In fact, healthcare providers give the first Depo-Provera injection during the first five days of a normal menstrual period to ensure the patient isn’t already pregnant. Fortunately, this is just a precautionary measure. There does not seem to be any link between taking Depo-Provera during pregnancy and the development of birth defects.

Not sure if you’re pregnant? It’s best to take a home pregnancy test or get a blood test as soon as possible to find out if you should stop taking the pill. If you have any questions about your birth control’s potential effects on an unexpected pregnancy, ask your medical provider.

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