Faint line on a pregnancy test: What does it mean?

If you see a positive line, you’re likely pregnant

Both at-home and doctor's urine pregnancy tests are cited to be 99% accurate if performed correctly and at the right time [2]. So, you can trust the test results you see on your at-home pregnancy test. But you’ll still need to book an appointment if the result comes back positive!  

If you take the at-home pregnancy test following the instructions correctly and see a faint line appear within the result reading window noted in the instructions (often between three and ten minutes, depending on the test), it's an indication that you're most likely pregnant.

When you're unsure about how to read the results of your at-home pregnancy test, always refer to the informational slip that comes with the pregnancy test. While at-home pregnancy tests work in a similar fashion, each might have slightly different instructions on how to read and interpret the results.

How do pregnancy tests work?

Pregnancy tests are made to detect the presence of the hormone hCG (human Chorionic Gonadotrophin), which is produced in your body when you’re pregnant [2]. At-home pregnancy tests check for the presence of this hormone in your urine, while a doctor can check for it in your blood. This hormone is produced in your body by cells of the placenta when you're pregnant [1]. 

The urine pregnancy tests work on a "sandwich principle": the hCG can act like a glue between mobile molecules tagged with color and fixed molecules on the test line [1]. So, simply put, the more hCG there is in your urine, the more colored molecules get stuck at the test line, and the darker the line looks! 

Some manufacturers have optimized their tests to be sensitive to much lower concentrations of hCG or to slightly different flavors of the hormone that are present in the first few weeks, which means they can detect pregnancy earlier [1].

HCG hormone starts being produced in your body when the fertilized egg implants in the uterus, which happens around 10 days after conception [2], although you will need to wait a few more days for it to rise to detectable levels [3]. In the first trimester of the pregnancy, hCG levels in your blood rise very rapidly, doubling almost every 24 hours during the first eight weeks and peaking at around 10 weeks of pregnancy [1], before decreasing again.

What does a positive pregnancy test result look like?

There are many at-home pregnancy tests available for you to choose from, and the positive result might look different depending on the type of pregnancy test you use:

• A bright pink or blue line next to the control line
• Two solid lines
• A plus and a minus
• Words "pregnant," "yes," or "positive"

When you take an at-home pregnancy test, read the instructions that come with it carefully beforehand. The instruction slip will tell you how to take the pregnancy test correctly and how to read and interpret the results for the particular test you're using.

The faint line on a pregnancy test might indicate that the hCG hormone is present in your urine, but the concentration is low because it's early in the pregnancy. The higher the concentration of hCG hormone in your body, the more prominent the positive line on your pregnancy test.

What does a faint line on a pregnancy test look like?

A faint line on a pregnancy test can be tricky to see. Some brands use blue dye in their pregnancy tests, so a strong positive might be a bright blue color, while a faint line might show up as light blue. Other brands and tests use red dye, so a strong positive might show up as a red line, while a faint line will appear as a light pink color.

How it shows up will depend on the type of at-home pregnancy test you use:

• If the test has a "+" sign, one line might appear bright while the other line might be less pronounced
• If the test has two lines, the control line will be bright color while the second line will be faint
• If the test has two lines, the faint line might appear thicker or thinner than the control line

Possible reasons for unclear results

You might be confused about why the result of your at-home pregnancy test is unclear, even if it looks like a positive result. Well, there can be several reasons why you see a faint line instead of a bright line:

• Your urine is too diluted: If you've drank a lot of water right before taking the test, the results might not be positive even if you are pregnant [1]. The best time to take the test is early in the morning when your urine is most concentrated [3].
• You're testing too soon: The recommended time to start testing for pregnancy is the day after you've missed your period [2], although certain early detection tests may already catch pregnancies a few days earlier [4]. Waiting can be challenging, especially when you're nervous or excited, but give it more time after conception for the hCG levels to rise [2].
• You didn't use the test correctly: You may not have followed the instructions on your packaging correctly, which may have resulted in unclear results. That's alright! Simply read the instructions and re-take a test.
• You used a less-sensitive test: Not all at-home pregnancy tests are created equally. Some are more sensitive than others, which means they’ll start showing a positive result even at lower concentrations of hCG. So, when testing for pregnancy early, choose the at-home pregnancy tests designed for early detection.
• Your hCG levels are extremely high: This may sound counterintuitive, but pregnancy tests can saturate and show a negative result if you have exceptionally high levels of hCG (called the “hook effect”) [1]. This is extremely rare, but it might happen if you’re using the very sensitive early ovulation tests later into your pregnancy, if you are expecting multiples, or if you have a molar pregnancy [5].

A faint positive vs. evaporation line

An evaporation line, sometimes referred to as an "evap line," is a false negative at-home pregnancy test result. It's often colorless and faint and can appear if you've left the pregnancy test for too long before reading the results [6].

A faint positive line can be hard to decipher from an evaporation line because, in many cases, they can look similar, yet they appear for very different reasons. The evaporation line is why all at-home pregnancy instructions tell you to check the results within a couple of minutes and wait no longer than 10 minutes (on average) to read the results.

That's because an evaporation line appears when the urine starts to evaporate from the pregnancy test strip after some time. That might cause the second line to turn a greyish color and become visible.

When you take an at-home pregnancy test, always check the results within a couple of minutes and toss the test into the bin immediately afterwards to avoid any confusion.

If you're unsure whether you see a faint line or an evaporation line, consider this:

• The timing: Did the line appear within a couple of minutes after doing the test, or did it only show up after you've left the test to sit for a while?
• The color: Does the second line appear a similar color to the control line (light blue or light pink), or is it a colorless or grayish color?

What causes faint positive lines on a pregnancy test?

As we already briefly touched on earlier, there are various reasons why you might see a faint line on your at-home pregnancy test: you might be early in your pregnancy journey, the test might be expired, the instructions weren’t followed properly, you tested after you've drank lots of water, or you might be taking fertility medication.

How can I avoid getting faint lines on my pregnancy test?

Getting a faint line on your pregnancy test can be confusing and frustrating. To minimize the chances of unclear results, consider:

• Choosing the right time: Unless you're using an early detection pregnancy test, wait until you miss the first day of your period before doing a test for more accurate results.
• Checking the expiration date before use: Always double-check that the at-home test has not expired, and avoid using expired tests.
• Doing the test first thing in the morning: To avoid unclear results due to diluted urine, take the pregnancy test first thing in the morning before drinking any water.
• Reading and following the instructions carefully: Each pregnancy test will be a little bit different, so make sure you read and study the instructions beforehand for the best results.
• Consider seeing a doctor: If you're taking medication that may influence the results of your at-home pregnancy test, schedule an appointment with your doctor so they can determine whether you're pregnant.
• Trying a different at-home pregnancy test: Using a digital pregnancy test can eliminate the guessing game because it gives you the results in an easy, straightforward way.

These tips may help you avoid unclear results and confusion they might bring in the future.

What can cause a false positive pregnancy test?

A false positive pregnancy test is very rare, but it can happen. Most often, the reasons for a positive pregnancy test while not currently being pregnant are:

• Fertility medication: Taking certain fertility medications can raise your levels of hCG hormone, which might result in a false positive test [2].
• Recent birth, miscarriage, abortion: It takes up to 60 days for the hCG hormone to completely leave your system, so if you take a pregnancy test too soon, it might result in a false positive [1].  
• Perimenopause or post-menopause: Peri- or post-menopausal women can have slightly elevated levels of the hCG hormone in their bodies (coming from the pituitary gland and not a placenta), which is why the pregnancy test during these years might be positive even if you’re not pregnant [7]. 
• You used an expired test: The expiration date on at-home pregnancy tests may affect their accuracy. So, before you take another test, double-check the expiry date to make sure you're not using an invalid test.
• Miscarriage: The hCG levels might be elevated and then start to drop if you experience a miscarriage [8], which might show up as a faint line on a pregnancy test.
• Ectopic pregnancy: An ectopic pregnancy occurs when the fertilized egg implants and starts growing outside the uterus, which can then rupture the fallopian tube and cause life-threatening internal bleeding [9]. Ectopic pregnancy might show up as a faint line on a pregnancy test.  
• Chemical pregnancy: Chemical pregnancy is a very early pregnancy loss that happens right after the embryo implants. Some early-detection pregnancy tests might show a faint line [10]. 

What to do if you see a faint line on a pregnancy test

If you take an at-home pregnancy test correctly and see a faint line, consider waiting a couple of days and then repeat the test. In case of pregnancy, your hCG levels should rise in those few days, which will give you a clearer result.

When to consult a doctor

After the positive at-home pregnancy test result, you should schedule an appointment with your doctor. They will perform another pregnancy test to confirm that you're pregnant. Afterwards, you can start planning your pregnancy journey.

If your at-home pregnancy test is confusing and you're not sure about the result, or you got a faint line and then a negative pregnancy test after a couple of days, you may also want to schedule a call with your healthcare provider. They may run some additional tests to help you figure out what's happening.

Different types of pregnancy tests

We have already discussed that there are two ways to detect pregnancy: through blood or urine. Blood tests have to be performed by a healthcare professional, but urine tests can be done in the comfort of your home. Not all at-home pregnancy tests are the same–there are three distinct types [4]:

• Midstream at-home pregnancy tests: A type of test that allows you to pee on a stick with an absorbent strip.
• Strip at-home pregnancy tests: A type of test when you pee in a cup and then dip a small absorbent strip into the urine.
• Cassette at-home pregnancy: A type of test in which you pee in a cup and then use a small pipette to draw the urine from the cup and add it to a cassette, which then shows the result.

Midstream pregnancy tests are the most convenient, popular, and easiest to use because you don't have to deal with handling urine. Midstream tests can either be digital or show the result with lines.

Digital tests eliminate the confusion about reading the results and trying to understand what they mean. But you can choose the right test for you and your budget or routine. Natural Cycles has partnered with Clearblue, and for our audience in the US, you can order Clearblue at-home pregnancy tests directly through the NC° app. We’ll even prompt you on the best day of your cycle to test in order to make the process of taking a pregnancy test as effortless and stress-free as possible.

Feel supported on your pregnancy journey with Natural Cycles

The Natural Cycles isn’t just an FDA-cleared birth control app, it’s designed to support you throughout your fertility journey. Natural Cycles can be used as a pregnancy planning tool just as much as it can be used as a natural birth control method — we're here to support you in every stage of your life.

NC° Plan Pregnancy allows you to be more in tune with your body on this exciting journey to conception. Once you’ve logged a positive pregnancy test in the app, you can switch to NC° Follow Pregnancy for information about what’s happening and the development of your baby throughout pregnancy. Why not find out if Natural could work for you?