So much excitement goes into taking a home pregnancy test. The two or three minutes between using the test and waiting for the results to appear are some of the longest minutes of most women’s lives. You can’t help but sit there for those few minutes wondering whether or not you’ll get the results you want. If you’re using a traditional test, you’ll wonder whether or not you’ll have to search for a faint second line to indicate pregnancy. If you’re taking a digital test, you’ll look immediately for the “Not” in front of the word “Pregnant” hoping that you don’t see it.

The moment of truth has finally arrived and it’s time to look at your home pregnancy test. You pick it up off the bathroom counter and take a deep breath. Then you look down; there’s nothing there. There are no lines; not even one. There aren’t any words; none. What has gone wrong? Your test should at least have one line on it even if you’re not pregnant or it should tell you in no uncertain terms that you’re not pregnant. However, your test is completely blank. What does a blank pregnancy test result mean?

A blank pregnancy test result typically means only one thing. You’ve used a defective or broken pregnancy test. Let’s look at the traditional pregnancy test. This test has two lines. The second appears only if you are indeed pregnant but the first appears as soon as you begin to saturate the test with your urine. This is called a test line. It appears for no other reason than to prove that the test is working accurately. If this line does not appear, your test is defective and not working.

If you’re using a digital pregnancy test, you’ll notice that there is an hourglass that appears in the digital screen once you begin to use the test and stays there while you wait on your results. This is the digital version of the test line. If this does not appear while you take the test, the test is defective.

How Long Are Pregnancy Test Results Good For?

Every pregnancy test is different. This is why manufacturers want their users to know that it is imperative to read the instructions each time they test. Even if you think you know how to use a pregnancy test, you don’t. One is completely different from another. One might want you to hold the test stick in your urine for a specific amount of time and another asks that you do it half the time. One asks that you wait two minutes to read the results and another asks that you wait one minute or even three minutes. All tests are different.

For that reason, it’s difficult to answer this particular question. Most pregnancy test results are only good for a few minutes. Typically, this means 10 minutes from the time you are to read the results until the results are no longer effective. While you might still notice that your results are visible after the 10 minute mark, this does not guarantee they are accurate. At this point, the results might no longer be accurate because the chemicals in the test are designed to work only so long, making them inaccurate after you wait too long to read the results.

For this reason, pregnancy test manufacturers recommend you read the results within the designated time frame to ensure that they are as accurate as possible. If you wait too long, discard the test and test again. However, be sure to read the instructions to see precisely how long results on the particular test you are using are valid. On a digital test, for example, your results might disappear after a few minutes and leave the test blank because the battery that operates them dies. With traditional tests, you might see evaporation lines on the pregnancy test that lead you to believe you are pregnant when you are, in fact, not pregnant.

How Long Do Pregnancy Test Results Remain Visible?

This is a question that depends entirely on your pregnancy test. For example, a digital test you used with your first pregnancy might have contained results that remained visible for days – and you know because you kept the test for sentimental purposes. However, you might use the same brand test with your second pregnancy and realize that the results have disappeared from the results window after an hour. With digital tests it all depends on the battery life inside the digital result window.

With traditional tests, your results will remain visible for an extended period of time, but usually not accurately for more than 10 minutes or so. If you have a negative test result, your results might be visible for only a short time before evaporation lines begin to appear on the test, tricking some women into believing they are expecting. Once your urine begins to dry on and inside the test it leaves a line in the area where your positive test result would have appeared. Sometimes it’s too faint to notice and sometimes it’s very obvious. This is called an evaporation line because it’s the evaporation of your urine as it dries.

Evaporation lines are not prolonged positive results, which is why pregnancy test instructions warn you frequently to only view results within the specified time frame. If you wait a day or more to read them, your results might not be visible anymore. However, if your traditional test results are positive and you decide to keep the test, chances are good that your test will keep the results visible for weeks at a time. Some women still have their tests from years before and claim they can still see the positive results they were hoping so much to see when they tested. Essentially, it’s best to read the results when they are visible and accurate within a few minutes of testing.