What week should i take a pregnancy test

• There are two main types of pregnancy tests: urine and blood tests.
• Take a home urine test after your next missed period — anywhere from 14 to 18 days after conception.
• Blood tests are more sensitive and can tell you if you're pregnant 6 to 14 days after conception.

You have two options when it comes time to see if you have a baby on board.

The most common is an at-home urine pregnancy test, available over the counter, though you can take a urine pregnancy test at a medical clinic. Another option is a blood test performed at a medical clinic.

"Both tests check for a hormone called human chorionic gonadotropin, or hCG," says Crystal Newby, MD, of Kansas City Ob-Gyn. "This hormone is produced after a fertilized egg attaches to the wall of your uterus."

The egg typically attaches 6 days after fertilization, at which point, hCG levels in your blood and urine will increase for the next 6 to 10 weeks. Once hCG levels are high enough, you can expect an accurate reading, but not before then. 

When should you take a blood pregnancy test? 

Depending on a woman's cycle, a blood test can detect pregnancy between 6 and 14 days after conception.

Blood tests for pregnancy are more sensitive to hCG than home pregnancy tests. They can detect this hormone in low quantities and tell you if you're pregnant sooner than a home test.

While blood tests can provide results sooner than home pregnancy tests, they are usually more expensive and take longer to provide results because the blood must be sent to a lab for analysis. 

If the lab is in-house then it will take a few hours. But if the lab is at a different location, it could take several days to learn the results.

When should you take a home pregnancy test?

Most home pregnancy tests advise you to take the test after you miss your next period. If you have a standard 28-day cycle, you'll be most fertile two to three weeks before your period. 

So if you get pregnant during that fertility window, you'll need to wait at least 14 to 18 days after conception to take a home pregnancy test.

If you get a negative result and suspect you're pregnant, check the instructions on the box. Home pregnancy tests typically recommend retaking the test 5 to 7 days later, when the hCG levels in your body will be higher.

This type of result is called a "false negative." Sometimes you can receive a false negative result if you take a pregnancy test too soon when your hCG levels are too low for the test to detect them accurately.

Moreover, recent miscarriages, fertility drugs, and rare hCG secreting tumors can interfere with the results of at-home urine tests. If you receive conflicting results after taking a home pregnancy test multiple times, doctors recommend a blood test.

How accurate are pregnancy tests?

Blood pregnancy tests are considered by doctors to be 99% accurate. Quantitative blood tests (also called beta hCG tests) are the most accurate blood tests and can help doctors tell the exact age of the fetus and play a role in detecting any abnormalities.

If you follow directions, home pregnancy tests are an estimated 97% to 99% accurate. If you perform a urine pregnancy test in a lab setting, like at your doctor's office, the accuracy will be closer to 99%. It's important to make sure that you check the expiration date on your home test, as it can affect the accuracy of the results.

After taking either a blood or urine test, it's important to confirm the pregnancy with an early ultrasound.

Insider's takeaway

Home pregnancy tests can provide results faster and be more convenient than a blood test. But you'll probably have to wait longer to receive accurate results.

You can expect accurate results from a blood pregnancy test as soon as 6 to 14 days after conception. Because the test must be analyzed in a lab, it could take up to several days to get the results.

To get the most accurate reading from a home urine test, wait until your missed period. This can come anywhere between 14 to 18 days after conception. If you get a negative result, you can try taking a home test again in 5 to 7 days to see if you have higher amounts of detectable hCG in your body.

Blood tests are considered to be 99% accurate, while home pregnancy tests are around 97% to 99% accurate. Regardless, you should confirm your results by getting an ultrasound.

Denice Rackley is a freelance writer for Insider.

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Although you might be eager to take a pregnancy test as soon as possible, it’s best to wait until your period is a week late to get the most accurate result. If you can’t wait until your period, let at least one to two weeks pass after you have sex before taking a pregnancy test. 

It’s important to wait, because your body needs to develop enough of the pregnancy hormone hCG that a pregnancy test can detect it. In most cases, home pregnancy tests can detect levels of hCG around 10 days after successful implantation of an egg (which doesn’t happen immediately after sex). If you take the test too early, you might get a negative result (even if you are pregnant). 

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This doesn’t mean you can’t take a pregnancy test later in the day. It just means that you’re more likely to get a false-negative, especially if you’ve been drinking a lot of water. It’s easy to forget in the morning, so it might be helpful to leave yourself a note the night before. You can close the lid of the toilet and leave a note there to remind yourself. 

What if you have an unconventional sleep schedule and can’t test your urine first thing in the morning? You can increase the level of hCG in your urine by not using the bathroom for at least four hours. 

Before taking a pregnancy test, don’t drink more water than you normally would. Drinking a lot of water can dilute your urine and affect the result of your test. 

If you got a negative result but still think you might be pregnant, take the test again after several days. False positives and false negatives are rare, but they do happen. Repeating a test can also be a good idea.

Taking a pregnancy test sooner than eight days past your ovulation (DPO) might result in a false negative. This is because fertilized eggs don’t start producing the pregnancy hormone that tests detect — hCG — until after implantation is complete.

About 85 percent of the time, implantation occurs 6–10 days after ovulation. After implantation, your hCG levels will start doubling every 48 hours — you can use our online hCG calculator to track your hCG levels at home. At this point, pregnancy tests will be able to measure your hCG levels, ensuring a positive result if you’re pregnant. 

Maybe you’ve taken a home pregnancy test, but now your health care provider is suggesting you take a blood test. What exactly is and when should you take a blood pregnancy test? 

Home pregnancy tests measure the levels of hCG in your urine. A blood pregnancy test measures the hCG levels in your blood. Health care providers suggest taking a blood test because they’re more sensitive and can offer more information than a home urine test. 

The best time to take a blood pregnancy test is if your period is several days late. If your home pregnancy tests are negative, but you’re experiencing all the symptoms of pregnancy, it’s a good idea to take a blood test. 

The most accurate blood tests are quantitative blood pregnancy tests, because they determine the exact amount of hCG in your blood. This is important because it can tell your health care provider if you’re pregnant or if you need to do another test in a few days.

Health care providers also recommend blood tests if you’ve experienced an ectopic pregnancy or a miscarriage in the past. This ensures your health care provider will be able to observe your hCG levels more closely in the first weeks of your pregnancy. 

You might wonder when to take a pregnancy test to get accurate results. Whether you’re hoping for a positive or a negative, taking a test the week after your missed period is probably the best way to find out. If you’re in a hurry, you can try taking a test at least one to two weeks after sex, but the results may not be as accurate. 

For best results, take the pregnancy test in the morning. First-morning urine exhibits the highest concentration of hCG. Taking your pregnancy test sooner than eight days past ovulation might result in a false negative. Blood tests are more sensitive and can offer more information than a home urine test.

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