What Does a Faint Line on a Pregnancy Test Mean?

Imagine this: You have been trying to conceive and you missed your period, so you take a pregnancy test to see if this is the month you’re finally expecting. But when the time comes to check the results, you see a faint line—not a bold, definitely-pregnant line—but a barely-there line that leaves you wondering just how reliable this test result is. Are you pregnant or not?

If getting a faint line on a pregnancy test is something you've experienced, it is normal to feel frustrated and concerned. But rest assured, we have answers for you. We talked to several experts about what exactly a faint line on a pregnancy test could indicate, and when to check in with a health care provider.

What Do Those Lines on a Pregnancy Test Mean, Anyway?

If you're using a home pregnancy test that displays lines in the result window, you'll notice the first one shortly after the kit is exposed to your urine sample. This initial line is referred to as the control line, and it's there to indicate that the test is working as it should. If the control line does not appear, your test should be discarded, as it's likely not going to give you an accurate result.

The second line that appears on a home pregnancy testing kit is referred to as the test line. This line will only appear if the amount of human chorionic gonadotropin (hCG) in your urine is at high enough levels to be detected, points out Kate Woeber, PhD, MPH, CNM, FACNM, an associate professor in residence and the Midwifery Program Director at the University of Nevada, Las Vegas.

There are other types of home pregnancy tests beyond the ones that show those standard two lines; others might use a plus sign to indicate pregnancy, and there are also digital versions as well.

What Causes a Faint Line on a Pregnancy Test?

If you're taking a home pregnancy test and encounter a faint line, it's understandable if you're concerned or confused. Here are a few reasons you might see a faint line on a pregnancy test.

You're Pregnant—But There's Not Enough hCG in Your Urine Yet

A faint line could very well indicate that the urine used for the sample is pretty diluted, or that it’s very early in the pregnancy—there is just enough hCG to turn the test positive, says Woeber. Keep in mind that hCG increases exponentially when you are pregnant, so even though your line may be faint now, it will likely be more visible if you take your test again in a day or two.

Often, a line, no matter how faint, indicates a positive result, adds Oliver Shih-Jwo Huang, MD PhD, the laboratory director at Innovative Health Diagnostics. “However, each test is different, and it's important to follow the instructions precisely. If there's uncertainty, it's always a good idea to retake the test.”

You're Not Pregnant, and the Faint Line Is an Evaporation Line

If you wait too long to view your results, the urine in the pregnancy test can dry up, resulting in a faint line that's known as an evaporation line. "An evaporation line may be grayish in appearance and can occur about 10 minutes after taking the test," explains Dan Nayot, MD, BSc, MSc, FRCSC, GREI, a reproductive endocrinologist, infertility specialist, and chief medical advisor at Bird & Be.

In the event you aren’t sure if you followed the kit’s directions accurately, you can always wait a couple of days and take another pregnancy test, Woeber suggests.

Additional Reasons for a Faint Line on a Pregnancy Test

Other possible reasons for a faint line on a pregnancy test include a chemical pregnancy, or a very early miscarriage, some fertility conditions, and certain fertility/IVF medications that can interfere with results. Studies have also shown that perimenopausal people can have higher hCG levels in their system. Meanwhile, someone who is post-menopausal may also have a higher hCG and could have a positive pregnancy test even if they are not pregnant, points out Dr. Nayot.

If you're unclear on your results, it's important to keep testing—both at home, and possibly with a health care provider too. "It is best to also obtain a serum (blood) hCG level to correlate," advises Shvetha Murthy Zarek, M.D., F.A.C.O.G., a fertility specialist and medical IVF director of Oma Fertility in St. Louis. "Depending on these results, your provider may ask for a repeat blood hCG test to follow your hCG trend, and/or recommend an ultrasound."

Are Pregnancy Tests Ever Wrong?

Unfortunately, false positives and negatives can both happen with at-home pregnancy tests. For instance, if you had a pregnancy loss and there is still hCG in your system, you may get a false positive, Dr. Nayot says, adding: “If you’re in fertility treatment, and taking certain fertility medications, then you may get a positive reading as well.” 

There also is an element of user error. Not keeping the test in the urine long enough or flooding it with urine for too long could potentially alter results. “It’s important to read the instructions and take the test per the specific steps indicated," Dr. Nayot adds.

As for false negatives, the culprit is usually taking the test too soon. False negatives on a pregnancy test are likely to occur if the level of hCG isn’t high enough yet to result in a positive test. "Someone who thinks they’re pregnant but has a negative test might take another test in a couple of days," advises Dr. Woeber, adding that the morning is the best time for an at-home pregnancy test. "By then, their hCG level should be higher and easier for the test to detect." 

What to Know About Blood Tests

Blood is far more reliable for monitoring hCG levels. That's because blood maintains a fairly steady composition at all times, thus making it easier to monitor changes in chemicals such as hCG. That's why quantitative hCG blood tests over a period of days are far more reliable that urine tests for monitoring hCG levels.

When to Contact a Health Care Provider

If you see a faint line on a pregnancy test, the first thing to do is take a deep breath! There are several factors at play that could be contributing to those confusing results. You may want to start with retaking the test in a couple of days and seeing how the information changes.

That said, if you’re consistently seeing that barely-there line, it may be time to pay a visit a health care provider. "A blood test can confirm without any doubt whether you are (or are not) pregnant," explains Dr. Nayot, adding that more testing can also help shed light on why you received unclear results to begin with.

Additional reporting by Krissi Danielsson.