Illustration: Emma Günther
How soon after unprotected sex should you take a pregnancy test?
Everything you need to know about taking a pregnancy test
Top things to know:
Taking a pregnancy test too early can give a false negative result
Not following home test directions can lead to incorrect results
Blood tests usually detect pregnancy sooner than urine tests
If you’ve recently had unprotected sex and are not trying to conceive, consider using emergency contraception as soon as possible
If you’ve recently had unprotected sex (or any situation where sperm may have come in contact with your genitals) and your period is late, it can be stressful—especially if you’re not trying to get pregnant.
You may be wondering:
How soon can I take a pregnancy test?
Which kind of test is most accurate?
When should I see a healthcare provider?
This article will guide you through the basics of when and how to test if you think you might be pregnant. If you’re trying to conceive, we have a separate article on pregnancy tests for you.
Note: Access to reproductive healthcare, including pregnancy tests and abortion services, varies depending on where you live. In a post-Roe environment in the United States, regulations may differ from state to state. If you need support, seek legal and medical resources in your area, or reach out to a trusted healthcare provider or advocacy organization.
How soon can you take a pregnancy test?
Most home pregnancy tests (the kind you pick up at the drugstore) can give you an accurate result once your period is at least a few days late, or about two weeks after your last unprotected sexual encounter.
It’s important to remember that pregnancy doesn’t actually start the moment you have sex. It can take up to six days for the sperm and egg to meet and form a fertilized egg (zygote). After that, the fertilized egg needs several more days to grow, make its way to the uterus, and implant into the uterine lining. So, from the day you have sex to the day a pregnancy can be detected, the process can span 2–3 weeks (1).
Emergency contraception
If you’ve had unprotected sex in the past few days and don’t want to be pregnant, you can use emergency contraception (EC), also known as the “morning-after pill” or “Plan B.” EC is most effective the sooner you take it, but can be taken up to five days after unprotected sex (2).
In the USA, EC containing levonorgestrel (brand name Plan B) is available over-the-counter without a prescription, while EC containing ulipristal acetate (brand name Ella) requires a prescription (2-4). Availability can vary by location, so check with your local pharmacy, clinic, or community health center for more information.
When to take a pregnancy test if you have a regular menstrual cycle
The highest risk of pregnancy usually falls around the middle of the cycle and up to about two weeks before your anticipated period (when most people ovulate) (5). Sperm exposure at the beginning or end of the cycle typically poses less risk of pregnancy because ovulation is less likely during those times (5).
Keep in mind that the ovulation day and fertile window displayed in the Clue app are only estimates and cannot be used to prevent pregnancy—your actual day of ovulation can vary from cycle to cycle.
You can take a pregnancy test as soon as you miss a period. If you get a negative result but still haven’t had your period a week later, take another test or contact your healthcare provider.
When to take a pregnancy test if you have an irregular cycle
If your period is unpredictable, with a 7–9 day (or more) difference between your shortest and longest cycles , it can be harder to know when you ovulate (5,6). In this case, unprotected sex or exposure to sperm on your genitals at any time represents a higher risk of pregnancy.
If you’re unsure when your period is due, aim to take a pregnancy test about two weeks after your last unprotected sexual encounter. If you get a negative result but still haven’t had your period a week later, take another test or visit your healthcare provider.
If you are using an active form of natural birth control (aka fertility awareness-based methods or natural family planning), you’ll have a better idea of your ovulation timing and can use that to estimate your risk of pregnancy (7). Keep in mind that most period tracking apps are not designed to be used as contraception.
(Remember, any unprotected sex at any time can also increase your risk of sexually transmitted infections (STIs), so consider getting tested for STIs as well.)
What’s the difference between home pregnancy tests and tests at a doctor’s office?
Both home and clinical tests detect human chorionic gonadotropin (hCG), a hormone the body produces in early pregnancy (8).
Home pregnancy tests (urine tests)
Often called “pee on a stick” tests, these show a positive or negative result based on whether your hCG levels meet a certain threshold (8).
These tests often give a false negative result if taken too early after a missed period (9).
If you get a negative result but still haven’t had your period a week later, it’s a good idea to take another test a few days later or visit your healthcare provider.
Healthcare providers' tests
Healthcare providers often offer both urine tests and blood tests for hCG.
Urine tests: Similar to home tests, but the results tend to be more reliable as there’s less chance of user error (10).
Blood tests: These measure the exact amount of hCG in your bloodstream, providing more detailed results (8).
How to use a home pregnancy test
Check the expiry date: Make sure the test is not expired.
Read the instructions: Each brand can have different directions. Not following them can lead to inaccurate results (10).
When to collect urine: You can test at any time of day because hCG production does not change throughout the day (11-13). However, if you drink large amounts of fluids, it can dilute your urine and affect the test’s accuracy. Consider taking the test first thing in the morning when your urine is more concentrated (10,14).
Confirm the results: Whether your result is positive or negative, it’s a good idea to follow up with a healthcare provider if possible. Home tests are less sensitive than those done in a healthcare provider’s office, and there’s also more chance for human error (10).
Can you get a false negative pregnancy test result?
Yes. The most common cause of a false negative result is testing too soon after conception (before hCG levels are high enough to be detected). If ovulation occurs later than usual, it can also delay a positive result, meaning you could get a negative test result even if you are pregnant (15).
Waiting about a week after a missed period (or two weeks after unprotected sex) to take a home pregnancy test will reduce the chances of a false negative (10).
That being said, if you live in a place where there’s limited time to make reproductive health decisions, it’s better to test early and test again a few days later, rather than waiting too long to test initially.
Can you get a false positive pregnancy test result?
Yes, but this is rare (17). A positive result can also be caused by:
A very early pregnancy loss soon after implantation
hCG production from certain types of tumors
Pituitary hCG secretion, typically in people going through perimenopause
An hCG injection administered as part of infertility treatment (9)
Medications generally don’t cause false positives unless they contain hCG (18). If you think your medication might be interfering with pregnancy test results, talk with your healthcare provider.
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When to see a healthcare provider
If you are unsure about the results of a home test or want to verify them, visit a healthcare provider. You can get confidential urine or blood testing at most clinics. If you’re transgender, there are many organizations worldwide that can help you find a trans-friendly ob/gyn.
If you’ve had a negative pregnancy test and haven’t had a period in more than 90 days, visit a healthcare provider. Tell them about your previous periods, cycle length and heaviness, and any other symptoms you’ve noticed. They may want to run a few tests to check if your cycle is being affected by another health condition.
Doing a pregnancy test can be emotional — whatever the results
Remember, you’re not alone in this. Consider reaching out to someone you trust for support. If you’re not sure where to turn, confidential counseling is available at most healthcare providers’ offices and clinics.
Scarleteen offers trans-inclusive support for teens and young adults via message boards, SMS and online chat. If you’re in the United States or Canada you can call the All-Options Talkline toll-free at 1–888–493–0092. The International Planned Parenthood Federation lists member associations in over 170 countries on their website.
FAQs
Is five days after sex too early to test?
Yes. Five days is usually too early for a reliable result. Most tests won’t accurately detect hCG until at least two weeks after unprotected sex, or around the time your period is due (9).
How accurate are home pregnancy tests?
They’re highly accurate when used correctly after a missed period (or at least two weeks after the sexual encounter if you’re unsure when to expect your period). However, testing too early, or not following directions, can affect results (10). If in doubt, repeat the test or see a healthcare provider.
