How to Get Accurate Home Pregnancy Test Results

Here’s what to know about taking a home pregnancy test to feel confident in the result.

How Home Pregnancy Tests Work

Home pregnancy tests detect a pregnancy hormone called hCG in urine. This stands for human chorionic gonadotropin. “Humans make small quantities of hCG, but typically not enough to trigger a positive test, except in some rare circumstances,” says Devorah Aharon, M.D., a board-certified ob-gyn and fertility specialist at RMA of New York.

Once a person becomes pregnant, there’s a higher level of hCG in their urine. This is what a pregnancy test can pick up.

“Pregnancy tests are held to a high FDA standard, and most are 99% accurate at detecting hCG,” says Aharon.

When to Take a Home Pregnancy Test

With home pregnancy tests, timing is key. For the most accurate result, take it after you miss your period.

“We recommend taking a home pregnancy test 14 days after ovulation, or one to two days after missing your period,” says Aharon.

That’s because it takes time for hCG to increase enough for the test to detect it.

What About Early Result Pregnancy Tests?

Some pregnancy tests can detect very low levels of hCG and may work a few days before you miss your period. These include Proov Check and First Response Early Result.

“The more sensitive a test, the earlier it can detect pregnancy,” Aharon explains.

With early result tests, someone who’s pregnant can get a positive result before they miss their period. But some people could actually be pregnant and not yet have a high enough hCG level for the test to detect, says Aharon. HCG increases fast—it doubles every 48 to 72 hours. If you get a negative result and still miss your period, it’s recommended to test again in four to seven days. This will check to see if the hCG level rises enough to turn a test positive.

What Time of Day Should I Take It?

You can pee on a pregnancy test anytime of the day. But Aharon says that typically, the best time to test is first thing in the morning. “This is when urine will be more concentrated, making the hCG easier to detect,” she says.

How to Choose a Home Pregnancy Test

Most pregnancy tests are pretty similar. But there are a few differences to consider when choosing:

• Sensitivity: Read the box to see how accurate the test is on the day you’re taking it. This is most important if you’re testing early.
• Cost: If you’re looking for a low-cost pregnancy test, a drugstore or dollar store is a good place to start.
• Display type: Color change tests that show two lines or a plus sign for a positive result can sometimes be hard to read. Digital tests like Clearblue show the word “pregnant” or “yes” and may help remove doubts, says Aharon.
• Pink dye vs. blue dye: “We've seen people recommending against blue dye tests,” says Alan Lindemann, M.D., a board-certified ob-gyn and author of Safe Pregnancy Explained. “Evaporation can create shadowy lines that make the results harder to read.” This can cause confusion in reading blue dye tests.
• Expiration date: Never use an expired test. If it is past the expiration date, the test may not give you accurate results.

How to Take a Home Pregnancy Test

To use the test, follow the instructions that come with it. They will tell you exactly what to do. This includes whether you should pee directly onto the stick or dip the strip into a cup of urine. They will also tell you how long to wait before reading the test.

Have a watch or phone with a timer, so you can read the result at exactly the right time. If you wait too long, you may wind up with an evaporation line that could be confused with a positive pregnancy line, says Lindemann. This is a common way people get “false positive” test results.

Common Questions About Home Pregnancy Tests

Here are answers to common questions we’ve received about pregnancy tests:

What’s the most accurate pregnancy test?

“The most accurate and precise pregnancy test is what we call the quantitative blood hCG level,” says Lindemann. This is a blood test given by a doctor or midwife. If you want a firm yes or no, make an appointment.

I see a faint line or plus sign. What does that mean?

If the test was done correctly, it means that it detected hCG in your urine. This means you’re very likely pregnant. Follow up in a couple days with another test to confirm. Typically, the line should get darker as the hCG level rises over those few days.

The test is negative. Could I still be pregnant?

That depends on a few different factors. There are some things that could lead to a false negative:

• An expired or defective test. Make sure that the pregnancy test you’re using hasn’t expired or been damaged.
• Human error. Follow the directions carefully. “It could show a false negative if you’re using too much or too little urine, if you’re not following the directions on the container, or if you wait too long to view the results,” says Lindemann.
• Diluted urine. If you’re drinking a lot of water or testing late in the day, there won’t be as concentrated hCG in your urine.
• Taking the test very early. If it’s early, you might not have enough hCG in your urine for the test to pick up. Take another test in four to seven days, says Lindemann.
• Taking the test very late. “Ironically, the home urine pregnancy test may be false negative if you are too far along in your pregnancy,” says Lindemann. “At about 10 or 11 weeks, you have so much hCG that… it doesn’t register on the stick.” If you think this is possible, call your healthcare provider for a blood test.

If you’re sure you took your test correctly and in the right time frame, you probably aren’t pregnant. For confirmation, retest in two days if you don’t get your period, suggests Aharon.

My test is positive. What should I do now?

If you have a positive pregnancy test, you’re most likely pregnant. Contact an ob-gyn, family practice doctor, or midwife to get their recommendation. They may order a blood test to confirm your pregnancy if there’s uncertainty. If they feel sure you’re pregnant, schedule an appointment for your first prenatal visit.

Try to eat healthy, and avoid alcohol, marijuana, tobacco, and illegal drugs while you’re pregnant.

“Anyone trying to conceive should be taking prenatal vitamins, which contain folic acid,” says Aharon. Folic acid can reduce a specific type of birth defect called a neural tube defect. It’s best when started early, so ideally, you should be taking prenatal vitamins whether you’re pregnant or may be in the future. Healthy choices can help you and your future baby stay healthy.

You May Also Like:

• Ob-Gyn vs. Midwife: How to Choose Your Pregnancy Care Provider
• What’s Safe During Pregnancy: A Guide to Food and Drink
• The First Trimester: A Guide to Early Pregnancy