How to Take the Most Accurate Pregnancy Test at Home

Think you might be pregnant? An at-home pregnancy test is the quickest and easiest way to find out. Read our tips for getting the most accurate results possible.

For most people, taking a pregnancy test at home is the first way they found out that they are expecting. The only way to get a positive pregnancy test at home is for the test to detect the pregnancy hormone hCG. After a fertilized egg implants in your uterine lining, it starts creating a pregnancy hormone known as human chorionic gonadotropin (hCG). At-home pregnancy tests work by detecting trace amounts of hCG in your urine. They're relatively inexpensive, and they can be found at most drug stores and grocery stores. Are you wondering how to take a pregnancy test to get the most accurate results possible? Read our guide for everything you need to know.

Types of Pregnancy Tests

There are two main types of at-home pregnancy tests: digital and non-digital.

Non-digital pregnancy tests

These tests come in many different forms, including standard sticks and test strips. You can pee directly on some pregnancy sticks, while test strips should be dipped in a cup of urine. (Always read the packaging of your pregnancy test for your brand's specific instructions though.) Either way, the urine must soak on the pregnancy test for several minutes, and the results will appear on a screen.

Pregnancy tests contain antibodies coated with a chemical that bonds to hCG if it's present, delivering a positive result. Depending on your specific test, positive results are usually indicated by a plus sign, a faint line, or a color change. If the molecules do not bond with any hCG, you get a negative result. It's also very important to read the results within the time frame listed on the test, as waiting too long or reading it too quickly could give you an inaccurate amount.

Digital pregnancy tests

Digital tests look similar to non-digital pregnancy test, but they have a screen and they rely on a method called "rapid assay delivery," which might give results in only three minutes. This method combines a biochemical process with antibodies that detect hCG. With digital tests, there is no guesswork or wondering Is that a line? or Is that a color? A digital at-home test will simply say "pregnant" or "not pregnant." While digital tests are available at grocery stores and drug stores, they tend to be a little bit more expensive. There are a few caveats about digital pregnancy tests: they are more expensive than sticks or strips, so if you're a serial tester, keep that in mind; they tend to require higher amounts of hCG to deliver a clear result; and lastly, their tendency for errors are higher (typically, false negatives, because they need a higher level of hormones to give you a positive result).

How Long Should You Wait to Take a Pregnancy Test?

No matter what type of pregnancy test you choose, timing is key to getting accurate results. After conception, it takes a while for hCG to generate in your body. The very earliest possible time to get a positive pregnancy test is six days post-ovulation, but that's incredibly rare and requires everything to go exactly correctly in order to happen. Keep in mind that everyone's body is different and a BFP (big fat positive) requires several steps: first, you have to ovulate and because sperm can live for up to 5 days inside the female reproductive system, it can be hard to pinpoint the exact time of fertilization unless you're 100% sure of ovulation and intercourse timing; next, the fertilized egg has to travel down the fallopian tube and implant in to the uterus; lastly, it has to produce the hCG to levels detectable in the body. Sometimes hCG reaches detectable levels before missing your period—but sometimes it doesn't, says Daniel Roshan, M.D., an OB-GYN at Rosh Maternal-Fetal Medicine in New York City.

Because hCG levels double every 48 to 72 hours, according to Dr. Roshan, taking a pregnancy test after missing your period gives you a greater likelihood of accuracy. For those with irregular periods, a good rule of thumb is waiting three weeks after having sex.

Most manufacturers recommend that home pregnancy tests be taken twice, since results may vary if you take a test too soon. In some cases, if your hCG levels are too low to catch early on, you may get a false negative result. This is especially common if you take "early detection" tests that promise results three, four, or even five days before a missed period.

Woman Holding Pregnancy Test on Knees
George Rudy/Shutterstock

Are Pregnancy Tests Accurate?

Pregnancy tests are about 99% accurate when used correctly and taken on or after the day of your expected period. It's possible to get false negative results (when you're actually pregnant but the test says you aren't). The most common cause is taking the test too early, but it can also happen if you don't follow instructions. If you missed your period and it doesn't arrive after a few days, repeat the test or check with your doctor, suggests Marra Francis, M.D., a board-certified obstetrician and gynecologist. Irregular periods could be caused by illness, certain medications, low or excess body weight, excessive exercise, stress, or hormonal contraceptives.

Even rarer, it's possible to get false positive results (you're not pregnant but the test says you are). While false positives mainly happen to people taking fertility drugs, they can also be caused by an expired pregnancy test, recent miscarriage or abortion, pregnancy loss soon after implantation (chemical pregnancy), or ovarian tumors.

Here are some tips for increasing the accuracy of your pregnancy test:

  • Check the pregnancy test's expiration date before purchasing it. If it's expired, it may not work properly.
  • Many doctors recommend taking the test first thing in the morning, as the concentration of hCG in your urine is usually highest then.
  • Despite common misconception, you shouldn't chug liquids before taking a pregnancy test. Doing this can dilute hCG levels in your urine and lead to a false negative result.
  • Some medications, like prescription fertility drugs, might mess up the pregnancy test. Your doctor may recommend getting tested in the office for more promising results.
  • Improper usage and exposure to sunlight may also lead to inaccurate results. Always use the pregnancy test according to instructions.
  • Always read the test results within the recommended time frame.

The Pregnancy Test Is Positive—Now What?

If your test has a positive result and you've followed all of the steps correctly, it is safe to assume that you are, in fact, pregnant. The next step is calling a pregnancy care provider, who will likely schedule a prenatal appointment. For many people, a pregnancy blood test is not needed to confirm the pregnancy, but your doctor may want to schedule a first-trimester ultrasound, depending on your health history and current medical status. If you have them, you can also start taking some prenatal vitamins as you await your appointment.

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