How Accurate Are Pregnancy Tests?

Those early pregnancy symptoms sure do mimic the signs that your period is on the way, but a pregnancy test can help you determine if you should be reaching for your menstrual cup or pregnancy books. But if you’ve never taken a pregnancy test before, you might wonder how accurate are pregnancy tests?

In this post, we’ll answer all of your questions including:

• How accurate are pregnancy tests?
• What is the most accurate pregnancy test?
• Plus, what is the best early pregnancy test?

How Accurate Are Pregnancy Tests?

Fun fact: Ancient Egyptian women used to take urine-based pregnancy tests to find out if they were pregnant. Of course, their tests consisted of urinating on barley to see which seeds sprouted faster—not quite the same thing as running to your local drugstore to pick up a test! (source) Despite the very unorthodox method of testing, researchers at Harvard University believe these women were on to something: The hormones in the urine of a pregnant woman encouraged the growth of barley.

Today a pregnancy test, a tool that checks your urine for the presence of human chorionic gonadotropin, or hCG will do the trick—and with much more precision.

But when it comes to accuracy, there are two things to consider: sensitivity and timing.

• Some pregnancy tests, especially drugstore brands, have very low sensitivity levels. This means that there must be more hCG present (i.e. over 100mIU/hCG) before the test will read as positive; these high levels are not present until 7-10 days after a missed period.
  
• Other pregnancy tests have very high sensitivity levels. This means they can detect lower levels of hCG sooner. You may be able to get an accurate result sooner if you use one of these tests.

If you’re ever wondering how accurate are pregnancy tests, just remember: All pregnancy tests are accurate if you follow the instructions about when to test. What type of test you choose has more to do with how long you feel you can wait! 

Most Accurate Pregnancy Test

If you’ve ever seen the sheer number of tests available in the family planning aisle of the store, you know there are many pregnancy tests out there. And when you think you might be pregnant, you’re almost certainly wondering how accurate are pregnancy tests? And which one is the most accurate?

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Ideally, opt for a sensitive test. The most sensitive tests are capable of detecting very low levels of hCG to give you an accurate result earlier.

A perennial favorite, the First Response Early Result has an analytical sensitivity of 6.3 mIU/mL, which can provide an accurate result up to 6 days before a woman’s missed period (about 7-10 days past ovulation).

In fact, a 2011 study found that the First Response Early Result (FRER) demonstrated a sensitivity as low as 5.5 mIU/ml (source) and could detect more than 95 percent of pregnancies on the day of your missed period. (source)

Since most women want to know as soon as possible, these tests are very popular. Lots of mamas shared their experiences with this test with us:

I got a positive with a FRER 9 DPO. — Carla P.

With my second son, I had a positive test at 8 DPO. It took two more days for the digital to pick it up. — Margaret T.

I always use the FRER and start testing at like 7 DPO. These are the ones that always turn positive first, usually by day 8 or 9. I have 5 boys, and this is always my go-to for testing. — Erin M.

If you’re not sure when you ovulated, use our ovulation tracker to determine the best time to take a pregnancy test.

Pregnancy Test Comparison Chart

How Accurate Are Digital Pregnancy Tests?

Have you heard of “line eye syndrome?” It’s a phrase that’s often used if you’ve stared at a pink or blue dye test for so many hours that you’re not sure if you actually see a second line or if your eyes are playing tricks on you. Enter digital pregnancy tests. With a digital test, there is no eye straining, no line detection, and wondering “Is there a line or isn’t there?” With a digital test, you only have to read: “Pregnant” or “Not pregnant.”

But digital tests aren’t as sensitive as some of the other tests and require more hCG to return a positive result.

According to a study published in Current Medical Research and Opinion, the Clear Blue Digital pregnancy test was able to detect 25 IU/I (99% accurate from the day of your expected period), and all of the study participants were able to interpret the results with 100 percent accuracy. These tests are popular because they are easy to read, they just aren’t as accurate when it comes to early testing.

Tip: Test with the cheaper tests first. If you want to see the words “pregnant,” use the digital test a few days later.

How Accurate Are Wondfo Pregnancy Tests?

Many mamas who are charting (to achieve a pregnancy) start testing around 7 or 8 DPO to try and catch the first hint of a second line. But all of those pregnancy tests can get pricey. If you plan to test early, consider Wondfo pregnancy tests. At $9.95 for a 25-count package, these tests are just $0.39 each.

These test are low-frills—just test strips—but are still fairly sensitive at 25mIU/hCG. A pregnant mother may have 25mIU/hCG in her urine around 10 days after ovulation, and about 100mIU/hcg about 10-14 days after ovulation. (source)  

Note: The Wondfo product literature states that in order for the test to be true to that 25mIU/hCG sensitivity, you must make sure that you have the authentic product and not a counterfeit. Double check your product against the image color/size on the product website to ensure you have the real deal.

Is Pink Dye or Blue Dye More Accurate?

It’s a myth that blue dye tests do not work as well.

Remember, accuracy has to do with how sensitive the test is (which should be listed on the box or product information of the test) and when the test is taken. The dye is not what makes the test more or less sensitive. (source)

There is nothing wrong with blue dye tests, and they are often just as sensitive as pink dye tests. In fact, a blue dye test provides an accurate result (from the missed period day) with over 99 percent accuracy. (source)

So why are the forums filled with little love for the blue dye tests?

It’s due to the evaporation line. An evaporation line forms when the urine on the testing area begins to dry, leaving a very thin and faint, grayish line. Since gray is closer to the color blue than pink, an evaporation line can sometimes be mistaken for a positive pregnancy test. 

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Tip: If you’re worried about evaporation lines, never read a pregnancy test after the specified time on the instructions, or alternatively stick with the FRER pink dye test.

The Alternative to At-Home Pregnancy Tests

The most accurate and most sensitive pregnancy test isn’t a urine test; it’s a blood test.

Although modern pregnancy tests are very accurate when used correctly, there is a little wiggle room for error. For instance, if you take the test too early, or if you don’t use the first morning urine (which has the highest concentration of hCG), or if you take the test incorrectly (i.e. not getting enough urine on the dip stick), you might receive a false response. If you really need an answer ASAP, see your healthcare provider or visit a lab for a blood test.

Blood test sensitivity

Blood tests can detect hormone levels as low as 5mIU/ml. However, most doctors only confirm pregnancy when the readings reach between closer to 25mIU/ml, which is about 10 days post ovulation. (source)

Cost and location of blood tests

Blood tests are a little more expensive than a urine test, but they are readily available at labs. For instance, Healthchek is a lab that offers an hCG test for $35 (source), while Direct Labs offers the test for $49 (source). You can also check with your ob-gyn or midwife, since many doctor’s offices have on-site labs for these purposes.

Can You Get A Positive Test and Not Be Pregnant?

When it comes to pregnancy tests, false negatives are much more common than false positives. Still, it is technically possible to get a positive pregnancy test and not be pregnant. This usually happens as a result of an underlying condition, like a UTI, cyst, or recent miscarriage. Learn more about what can cause a false positive in this post.

Remember…

How accurate are pregnancy tests? Repeat after me: All pregnancy tests are highly accurate. Did you already get a positive test? Then, check out this post! If you want to test early, consider the FRER test. If you don’t get a positive pregnancy test right away, you may just have to wait a few more days to test again.