If you’re asking yourself “Am I pregnant?” you might want to try a home pregnancy test. All home pregnancy test kits measure human chorionic gonadotropin (hCG), the “pregnancy hormone” in urine. You can purchase these kits in all major grocery stores, pharmacies, and retailers in the United States, and you can take the test in the privacy of your own bathroom. Within a few minutes, you’ll have the answer to your question. Home pregnancy tests offer quick, accurate, and early results—some pregnancy test kits can be used before you have missed your period. The earlier you find out whether you’re pregnant, the sooner you can start taking optimal care of yourself. If the test result is positive—congratulations, you may have a baby on board! To find out for sure, you must have the result confirmed by a blood test and a thorough prenatal evaluation. This is essential to ensure a healthy pregnancy.
How Accurate Is a Home Pregnancy Test Kit?
The accuracy of a home pregnancy test kit depends on the following factors:
Timing. When you take the test can affect the result. The more advanced the pregnancy, the more accurate the test. The level of hCG in your body (urine and blood) begins to increase immediately after implantation of an embryo in the uterus. In a 28-day cycle, with ovulation occurring at day 14, hCG can be detected in urine or serum in minute quantities around day 23, or five days before your period is due.
Some home pregnancy test kits promise 99 percent accuracy at detecting hCG levels from the day of your expected period. However, hCG levels vary considerably among women. Also, the accuracy decreases each day before your period is expected. So if you take the test four days before your period is expected, the accuracy drops to about 60 percent. At the beginning of a normal pregnancy, the level of hCG rises rapidly and doubles about every two days. The higher the hCG level, the more likely a pregnancy test is able to detect it. For the most reliable results, perform the test one to two weeks after you miss your period.
Test sensitivity. Keep in mind that a home pregnancy test will provide a positive result only when there is a detectable level of hCG in your urine, and this level varies per test. Manufacturers of home pregnancy test kits are not required to list the hCG level that the kit can detect on their packaging. If the level is listed, it is given in milli-international units per milliliter (mIU/mL). This number will tell you the sensitivity of the test. For example, a test that can detect 20 mIU/mL of hCG has a higher sensitivity than a test that can detect 50 mIU/L of hCG. The lower the number, the sooner you should be able to tell you are pregnant. There are one or two home pregnancy tests on the market today that claim to be able to detect hCG levels as low as 10 mIU/mL. Most tests have an hCG detection limit of 20 mIU/mL, 25 mIU/mL, 40 mIU/mL, or 50 mIU/mL. If you want to know the exact hCG level detected, you should contact the manufacturer of the test.
Correct use. For most home pregnancy tests, you either hold a test strip in your urine stream or you collect your urine in a cup and dip your test strip into the cup. Taking a pregnancy test is easy, but it can be complicated by any nervousness, excitement, or other emotions you might be feeling. In some instances, the test result may be pale or faint. A faint line can occur for several reasons, the most common of which is failure to follow instructions properly. To avoid a confusing result, always read the test instructions first and don’t test too early. Doing the following can help you feel more confident about the test result:
- Use first morning urine.
- Don’t drink a lot of fluid before testing. This can dilute the urine.
- Check the labels of the medications you’re taking for possible drug interactions. Most commonly used over-the-counter medications will not affect the result.
- Don’t use a test past its expiration date.
For more pregnancy test tips, visit the Pregnancy Test Tips page.
How to Choose a Home Pregnancy Test Kit
You can choose from a variety of over-the-counter home pregnancy test kits. The following table lists well-known home pregnancy test kits by their brand names, their sensitivity (as reported by various online sources), and how to read the test. Many pregnancy tests will display a control window and a result window. The control tells you that you have performed the test correctly and it is functioning properly. The result tells you if you are pregnant or not. It can appear as a simple color band, a plus sign, or actual words or symbols.
Well-known home pregnancy test kits
|Pregnancy test||Sensitivity (hCG level detected)||How to read test|
|Answer||25 mIU/mL||One line means not pregnant; two lines means pregnant|
|Clearblue Easy||25 mIU/mL||A plus sign (+) in the display window indicates a pregnant result; a minus sign (?) indicates a not pregnant result|
|Clearblue Easy Digital||50 mIU/mL||“Pregnant” or “Not Pregnant” new Clearblue tests will also estimate how many weeks you are pregnant|
|e.p.t (error-proof test)||25 mIU/mL||A plus sign (+) in the display window indicates a pregnant result; a minus sign (?) indicates a not pregnant result|
|e.p.t digital||50 mIU/mL||“Pregnant” or “Not Pregnant”|
|Equate pregnancy test||25 mIU/mL||A plus sign (+) in the display window indicates a pregnant result; a minus sign (?) indicates a not pregnant result|
|Fact plus Pregnancy Test||40 mIU/mL|
|First Response Pregnancy||25 mIU/mL||One line means not pregnant; two lines means pregnant|
|First Response Digital||25 mIU/mL||“Yes +” or “No –” result|
Home pregnancy tests vary in price, depending on the format you choose and where you purchase the test. Most kits come with two or more tests. The cost can range between $6 and $30 for each kit. Your local drug store may offer less expensive generic versions of the kits listed in the Table. Free pregnancy tests may be available through pregnancy care and crisis centers in your area.
What to Do After Using a Home Pregnancy Test Kit
While home pregnancy tests are very effective, it is possible to get a positive result when you’re not actually pregnant. This is known as a false positive. You may also get a negative result from a home pregnancy test when you’re actually pregnant. This is known as a false negative. If you have a negative home pregnancy test and your period hasn’t begun, repeat the test in a few days or one week. If you continue to get negative test results and have missed your period, contact your healthcare provider. Although you may be pregnant, there are other possible causes for a missed period, including illness, strenuous exercise, weight loss, stress, and hormonal imbalances. A positive home pregnancy test always needs to be confirmed by your healthcare provider. The sooner you can begin prenatal care, the better.