How soon after your missed period should you test

If you’re trying to get pregnant, the best time to take a pregnancy test is one week after you’ve missed your period. Why? Because this is really the best way to prevent a false negative result (a negative test in someone who's actually pregnant) result.

Table of Contents Show

Brand name versus generic pregnancy tests
How to prevent a false negative result
Medications and test results
When to see your doctor
How do pregnancy tests work?
How accurate are pregnancy tests?
How soon can I take a pregnancy test?
Where can I get a pregnancy test?
What should I do if my pregnancy test is positive?
More questions from patients:

Home pregnancy tests can be used as early as the first day after your first missed period in women with regular/predictable monthly menses. If you have irregular periods, you can administer a test 14 days after intercourse, since you likely can’t pinpoint your exact time of ovulation.

Pregnancy tests detect a hormone called human chorionic gonadotropin (HCG), which is produced in early pregnancy. The production of this hormone begins slowly and increases as the pregnancy grows. Standard urine pregnancy tests will detect the HCG level when it reaches 20-50 milliunits/milliliters.

If you take a test too soon (before you've missed your period), the levels of HCG may not be high enough to detect a pregnancy and it could cause a negative result, even though you're actually pregnant.

I advise my patients to wait at least one day after you miss your period. If you wait one week after a missed period, the chance of a false negative is very low if you have a normal monthly menstrual cycle.

Brand name versus generic pregnancy tests

Home pregnancy tests, both brand name and generic, are very accurate at detecting the HCG hormone and any positive result, even a faint line, can be considered positive. HCG is only produced by a pregnancy; any positive result indicates a pregnancy.

You don’t need a serum (blood) pregnancy test to confirm pregnancy. Both urine and blood detect HCG, although the blood test is more sensitive and can detect HCG levels at much lower levels than a urine test. In certain situations, your doctor may want to perform a blood HCG test but it’s not typically needed to confirm a pregnancy.

Although most tests advertise 99% accuracy, the ability of a particular brand to detect HCG at levels less than 50 ml may vary. Some brands may be better able to detect lower levels of HCG than others. If your HCG level is more than 50 ml, which is the detection rate of most tests, even generic tests will detect a pregnancy accurately.

How to prevent a false negative result

The number one cause of a false negative test is taking the test too soon after you conceive. Also, if you don’t follow the test instructions carefully, it could affect your result.

Urine, even in women who drink large amounts of water, should still yield a positive result. But urine shouldn’t be diluted with water before taking a test. A good time to take the test is in the morning when you first wake up.

If a test is negative in a woman who suspects she’s pregnant or if she has irregular cycles, she should repeat the test in one week.

Medications and test results

Medications don’t typically interfere with results, neither causing false positive nor false negative. Only a medication containing HCG would affect the result.

When to see your doctor

Although home tests can detect a pregnancy, it gives no information as to viability. It’s important to make an appointment with your doctor to confirm your pregnancy and to detect a fetal heart rate through an ultrasound (usually at six to 10 weeks). If you have a positive pregnancy test, your obstetrician can provide information about warning signs of an abnormal or worrisome pregnancy and can advise you on when to make an appointment to confirm your pregnancy.

How do pregnancy tests work?

Pregnancy tests are an easy and accurate way to find out if you’re pregnant — you just pee on a stick. They’re inexpensive and available at most drug and grocery stores.

How accurate are pregnancy tests?

Pregnancy tests are super accurate when you use them correctly. The pregnancy tests you get at the drugstore work 99 out of 100 times. They’re just as accurate as a urine pregnancy test that you’d get at a doctor’s office.

Pregnancy tests work by checking your urine (pee) for a hormone called human chorionic gonadotropin (HCG). Your body only makes this hormone if you’re pregnant. HCG is released when a fertilized egg attaches to the lining of your uterus — when pregnancy begins. If your pregnancy test results are positive, it means you're pregnant. If they’re negative, it means you’re not pregnant.

Pregnancy tests are most accurate when you take them after you’ve already missed your period.

A pregnancy test will be less accurate if it’s expired or if you don’t use it the right way. So always check the expiration date on the package, and carefully read the directions that come with your pregnancy test.

How soon can I take a pregnancy test?

You can take a pregnancy test anytime after your period is late — that’s when they work the best. It’s a good idea to take a pregnancy test as soon as possible if you miss your period or think you might be pregnant.

The earlier you know you’re pregnant, the sooner you can start thinking about your options and get whatever care you need to stay healthy.

Many pregnancy tests say they work a few days before a missed period, but the results are usually less accurate then. Read the label on your pregnancy test to find out when to take a pregnancy test and how accurate it’ll be.

Sometimes a pregnancy test is able to find pregnancy hormones in your urine as early as 10 days after unprotected sex. But these results aren’t super reliable, and you may get a false positive or false negative test result.

If your periods are very irregular, or you don’t get periods at all for one reason or another, your best bet for accurate results is to take a pregnancy test 3 weeks after sex.

Where can I get a pregnancy test?

You can buy a pregnancy test at your local pharmacy, drugstore, grocery store, and some convenience or dollar stores. Pregnancy tests are usually inexpensive — they can cost as little as a dollar. Sometimes you can get a free pregnancy test at certain health centers.

You can also get a pregnancy test from your nurse or doctor, community clinic, or local Planned Parenthood Health Center. Most health centers use the same urine pregnancy tests that you can buy in stores. Sometimes they use a blood test to test for pregnancy, but that’s usually only under special circumstances.

But be careful when looking for a reliable health center, because there are fake clinics out there called Crisis Pregnancy Centers. Crisis Pregnancy Centers give free pregnancy tests and claim to offer information and help. But they’re run by people who may not be medical professionals, and don’t believe in giving you honest facts about pregnancy and all of your options. Crisis pregnancy centers are often located very close to Planned Parenthood health centers or other real medical centers, and have similar names — they do this to confuse people and trick them into visiting their center instead.

Your nearest Planned Parenthood health center can help you find a safe place to get a pregnancy test in your area.

What should I do if my pregnancy test is positive?

If you take a pregnancy test after you miss your period and the result is positive, that means you’re pregnant. You can always take another test to be sure, if you want.

You may want to go to a nurse or doctor, family planning clinic, or local Planned Parenthood Health Center to get a follow-up test. They’ll talk with you about your pregnancy options, and help get you the care you need. Be careful not to visit a Crisis Pregnancy Center, because they might not give you real medical care or truthful information about your pregnancy and all of your options.