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Can birth control affect a home pregnancy test? More of your top testing questions, answered

Home pregnancy tests (HPT) are straightforward and easy-to-use, but that doesn’t mean you’ll never have questions about using them, especially when certain health conditions or scenarios are involved. If your curiosity wasn’t satisfied in our first post on pressing HPT questions, let’s review a few more common inquiries about home pregnancy tests and their answers.

Can birth control affect a pregnancy test?

Most medicines — including over-the-counter and prescription medications like hormonal birth control — should not affect the results of a home pregnancy test.1 Home pregnancy tests, including all Clearblue® HPT tests, work by detecting human Chorionic Gonadotropin (hCG), a hormone produced during pregnancy.2 This hormone is not a component of common birth control methods, including the pill.1 So if you’re on the pill, don’t worry about it affecting your HPT result.

That said, the first day of your period is often used to help calculate when you should take a pregnancy test. Some women may have irregular periods or no period while on birth control. If your period is irregular, try counting 36 days from the start of your last menstrual cycle or four weeks from the last time you had sex. At this point, your hCG levels should be high enough to detect the pregnancy if you are pregnant.1

Can you use a home pregnancy test if you have an IUD?

If you think you might be pregnant while using an intrauterine device (IUD), you can follow the standard instructions for how to take a pregnancy test at home. Your IUD should not affect your hCG levels, so it shouldn’t affect your result.1

As with hormonal birth control, the timing of a test while using an IUD is tricky, especially if your periods are inconsistent. According to The American College of Obstetricians and Gynecologists, IUDs generally claim to have a 0.02-0.8% chance of pregnancy.3 Between the slim odds of pregnancy and possible side effects of IUDs (changes in your period, nausea, headaches), it might be hard to tell if you’re pregnant.

If you are pregnant, see your doctor immediately. In the rare cases where pregnancy occurs while an IUD is in place, there is a higher-than-usual chance of it being an ectopic pregnancy — a serious condition that requires immediate medical attention.4 If it is not ectopic and you want to continue the pregnancy, your IUD should be removed. If the IUD remains in place during pregnancy, there are increased risks of miscarriage and infection.4

Can fertility treatments impact home pregnancy test results?

Getting a false positive result is rare; all Clearblue® pregnancy tests are over 99% accurate from the day you expect your period.5 But false positives can occur if you’re taking medications that contain hCG.

For example, if you’re undergoing in vitro fertilization (IVF) treatment, some fertility medications will increase the presence of hCG in your body. If you take an at-home test too early, the increased level of hCG may lead to a false positive. You can wait seven days following your embryo transfer to take a test at home, but many doctors will recommend coming to their office for a pregnancy test instead.6

Does the amount of urine affect a pregnancy test?

If you’re following Clearblue® Early Detection Pregnancy Test instructions, you will need to place the tip of the test in your urine stream for five seconds or place it in a urine sample collected in a clean, dry container for five seconds. The logistics are simple, but it’s easy to start overthinking the details. Does it matter how much you pee on a test?

Pregnancy tests require a specific amount of urine. If you’re worried about keeping precise time while urinating directly on the test, opt for using a container. It’s important to follow the instructions as accurately as you can. If you think you misjudged the time or volume (the urine level should not go above the plastic housing of the test stick), don’t be afraid to take another test.

Keep in mind that drinking too much water or other liquid can affect a pregnancy test. Drinking lots of liquid before testing dilutes the amount of hCG in your urine, making it harder for the test to detect, so try taking a test first thing in the morning, when hCG is more concentrated.

Should I avoid taking a test if I have a yeast infection? Or a UTI?

Over-the-counter treatments for yeast infections should not affect the results of a home pregnancy test. 1 Whether you have an infection or are undergoing treatment, you should be fine to test. In fact, a yeast infection could be caused by pregnancy.7

A UTI (or urinary tract infection) is another story. As part of your treatment, you should be drinking plenty of water or liquids to stay well hydrated.8 Like we mentioned previously, drinking excess liquids can skew the results of your pregnancy test. If you’re trying to conceive and develop a UTI, be sure to see your doctor for treatment and advice right away.

If you’re testing, remember to follow the instructions as precisely as possible. When in doubt, talk to your doctor about when and how to take a test while on specific medications or treatments. They’ll be able to lend advice tailored to your unique situation.



  1. “Pregnancy tests”, (2021), Office on Women’s Health, https://www.womenshealth.gov/a-z-topics/pregnancy-tests
  2. “Human Chorionic Gonadotropin (HCG),” (October 8, 2020), University of Michigan Health, Michigan Medicine, https://www.uofmhealth.org/health-library/hw42062
  3. “Effectiveness of Birth Control Methods,” (October 2021), The American College of Obstetricians and Gynecologists, https://www.acog.org/womens-health/infographics/effectiveness-of-birth-control-methods.
  4. “Long-Acting Reversible Contraception (LARC): Intrauterine Device (IUD) and Implant”, (November 2021), American College of Obstetricians and Gynecologists, https://www.acog.org/womens-health/faqs/long-acting-reversible-contraception-iud-and-implant
  5. >99% accurate at detecting typical pregnancy hormone levels. Note that hormone levels vary. See insert.
  6. “Testing for Pregnancy after IVF”, (June 28, 20190, The Fertility Institute of New Orleans, https://fertilityinstitute.com/blog/testing-for-pregnancy-after-ivf/
  7. “Vulvovaginal Health”, (January 2022), American College of Obstetricians and Gynecologists, https://www.acog.org/womens-health/faqs/vulvovaginal-health
  8. “Urinary Tract Infection”, (October 6, 2021), Centers for Disease Control and Prevention, https://www.cdc.gov/antibiotic-use/uti.html