How Soon After Unprotected Sex Can I Test for Pregnancy?

Pregnancy is a life-changing event, whether it’s a planned parenthood or because of missed birth control.

Most people try to take a pregnancy test as soon as possible after having unprotected sex, but this may affect the accuracy of results.  

I you take a pregnancy test too early, you risk getting a false negative result, which is when the test says you’re not pregnant even though you really are.

In this guide from PregnancyResource.org, we’ll go over how a pregnancy test works, and talk about the best time to take a test after unprotected sex for the most accurate results. 

How Does a Pregnancy Test Work?

There are two choices when it comes to pregnancy tests: urine tests and blood tests. 

Only a healthcare professional (usually your OB/GYN) can administer a blood test, and this is typically not the route for women who need to know if they’re pregnant as soon as possible. 

A quicker option is an at-home pregnancy test kit, which is available over-the-counter (meaning you don’t need a doctor’s prescription to get it).

A home test measures human chorionic gonadotropin (hCG) levels in the urine. HCG is a hormone that everyone has, but when you’re pregnant, your body ramps up its production to help the uterine lining thicken. 

HCG levels begin to increase soon after a fertilized egg implants into the uterus. On average, this happens about a week after conception.

Home pregnancy tests measure hCG using in your urine. Most tests ask you to place a few drops of urine on a designated test trip, and if high enough levels of hCG are present, there will be a color change on the strip to indicate pregnancy. 

Depending on which test you use, a positive result may appear as a double vertical line, a plus sign, or the word “pregnant.”

If you have a negative test result, the test will usually display “not pregnant,” a minus sign, or there may be no change in the display at all.  

What Is the Best Type of Pregnancy Test?

If you’re looking for the most accurate test, you don’t have to worry about picking the “best” pregnancy test. 

Studies show that all home pregnancy tests have a 99% accuracy rate if taken at the right time in the pregnancy. 

That said, pregnancy tests can have additional features that make them easier to use. 

Here are three factors to consider when buying a pregnancy test: 

1. Detection Time

More sensitive pregnancy tests can pick up on a type of hCG known as hCG-h that is produced early in pregnancy.

These tests can detect early pregnancy as soon as six days before some generic brands.

If you don’t want to wait until signs of pregnancy like a missed period to get pregnancy test results, investing in an early detection pregnancy test may be worth it. 

2. Testing Method 

All home pregnancy tests work by checking your urine for hCG levels.

First thing in the morning is usually the best time of the day for a test, as hCG can build up in your body as you sleep. 

What differs between tests is how the urine is placed on the test strip. Some pregnancy tests ask you to pee directly onto the testing stick.

Others may provide you with a cup to pee into so you can dip the test strip into the container for testing. Others may even provide you with a dropper for putting a few drops of urine onto the test.

Taking a pregnancy test can be stressful enough on its own. To keep from adding even more stress to the experience, make sure to get the type of test that’s as easy as possible for you to take. 

3. Display Type

The vertical line display is probably the most well-known feature of pregnancy tests.

This type of results display can be hard to read and may produce an ambiguous result, leading to the need to purchase another test. 

It’s better to get it right the first time with a clear display.

Some pregnancy tests will display your results as a plus sign (which means you’re pregnant) or a minus sign (which means you’re not pregnant).

If you can spend a little more on a pregnancy test, then a digital one is usually the easiest to read.

Once your results are ready, you will see either “pregnant” or “not pregnant” clearly displayed on the test — taking away the guesswork.

How Soon Can I Test for Pregnancy?

You may be tempted to take a pregnancy test soon after having unprotected sex.

However, you need to give your body time to build up hCG — otherwise, a pregnancy test won’t pick up on it. 

The earliest possible time you can take your pregnancy test is about eight days after conception. This is when hCG levels can begin to build up in some women.

However, at just eight days, there is no guarantee that your body has produced enough hCG to be detected by a pregnancy test. As such, you may not get an accurate result.

If you’re taking an early detection pregnancy test, you can usually use it as soon as five days before your next menstrual cycle.

Even with an early test, it’s still best to wait until your missed period for the most accurate results.

If your period is irregular, note the first day of your most recent cycle.

Count 30 days from the first day and take the test within days 30-35. 

If you get a positive pregnancy test, be sure to confirm it with your healthcare provider through a blood test.

Urine pregnancy tests may say you are pregnant but it is possible to have a false-positive result.

If you get a negative test result but miss your next period or start to get pregnancy symptoms such as morning sickness, it is best to visit your doctor and have them run a blood test for you.

In Conclusion

Although you may be anxious to take a pregnancy test as soon as possible, it’s best to wait until after your first missed period for the most accurate results.

If you’re excited to get the results, an early detection pregnancy test can tell you if you’re pregnant up to five days before generic pregnancy tests. 

References and Sources: 

Pregnancy | FDA 

Human Chorionic Gonadotropin: The Pregnancy Hormone and More | PMC 

Strips of Hope: Accuracy of Home Pregnancy Tests and New Developments | PMC