Quick Answer
Yes, you can take a pregnancy test at night. In fact, some sources recommend taking a pregnancy test with your first morning urine, as it contains the highest concentration of the pregnancy hormone hCG. This can increase the accuracy of the test. However, you can take a pregnancy test at any time of day and still get an accurate result as long as you have not urinated for at least 4 hours before taking the test.
When is the best time to take a pregnancy test?
The best time to take a pregnancy test is first thing in the morning, after your first pee of the day. Here’s why:
- Your urine is more concentrated in the morning, so there’s more hCG (the pregnancy hormone the test is looking for) in it.
- You haven’t drunk much water yet, so the urine isn’t diluted.
- If you’re testing before your missed period, the hormone may not have risen to detectable levels yet, so a morning test gives you the best shot at an accurate result.
That said, you can take a pregnancy test at any time of day and expect accurate results as long as you follow the test’s instructions. Here are some tips:
- Try not to pee for at least 4 hours before testing.
- Don’t drink too much liquid before testing.
- Read the instructions and follow them carefully.
- Check the test within the timeframe specified on the instructions (this is usually 5-10 minutes).
The more sensitive the test, the earlier you can test. Early response and early detection tests can often provide accurate results up to 6 days before your missed period. Traditional tests work best on the day or after your expected period.
How accurate are nighttime pregnancy tests?
Pregnancy tests work by detecting the pregnancy hormone human chorionic gonadotropin (hCG) in urine. hCG levels double roughly every 48 hours during early pregnancy.
As long as you have not urinated for at least 4 hours before taking the test, a nighttime pregnancy test can be just as accurate as a morning test. The concentration of hCG in urine peaks in the morning because it builds up overnight. However, unless you’re testing right before a missed period, there should be enough in your nighttime urine to get a reliable result.
Here’s a table with typical hCG levels during pregnancy:
| Weeks pregnant | hCG level range (mIU/mL)* |
|---|---|
| 3 weeks | 5 to 50 |
| 4 weeks | 10 to 750 |
| 5 to 6 weeks | 50 to 100,000 |
| 7 to 8 weeks | 5,000 to 200,000 |
| 9 to 12 weeks | 10,000 to 100,000 |
*mIU/mL = milli-international units per milliliter
As you can see, by 5 to 6 weeks the hCG level is high enough to be reliably detected by any pregnancy test, day or night. However, levels between 10 to 20 mIU/mL may cause a false negative if the urine is dilute. That’s why using first morning urine is recommended.
What if I get a negative pregnancy test at night?
If your pregnancy test is negative but you still think you may be pregnant, there are a few possibilities:
- You tested too early. Try again in a few days if your period still hasn’t arrived.
- Your urine was dilute. Test again with morning urine.
- The test is faulty. Try a different brand or get a blood test.
- You read the results outside the specified timeframe.
- You aren’t pregnant.
Certain medications can also cause false negatives by interfering with the test. If you get a negative but still suspect pregnancy, see your healthcare provider. They can do a urine test with greater sensitivity or order a blood test to check your hCG levels.
A blood test can detect hCG as early as 6 to 8 days after ovulation or conception. Urine tests won’t be positive until a few days after that when hCG has risen high enough to be excreted by the kidneys into urine.
Tips for the most accurate results
Follow these tips to maximize your chances of getting an accurate result, day or night:
- Read and follow test instructions carefully.
- Check the expiration date. Don’t use expired tests.
- Collect your urine in a clean cup, not directly on the test stick.
- Avoid excess liquids before testing. Try for concentrated urine.
- Hold the test stick in urine for the specified time.
- Lay the test flat while it develops.
- Don’t read results after the specified window (usually 5-10 minutes).
Pink dye tests may be easier to interpret than blue dye tests. Early detection tests are the most sensitive. Choose a reputable brand for best accuracy.
If you get an unexpected result, re-test with first morning urine or see a doctor for further evaluation. Home pregnancy tests are generally accurate when instructions are followed properly, but false results are possible.
When to see a doctor
See your doctor or obstetrician if:
- You get a positive result to confirm the pregnancy.
- You think you’re pregnant but keep getting negative home tests.
- Your periods are irregular and you don’t know when you ovulated.
- You have symptoms of an ectopic pregnancy like abdominal pain.
Your doctor can order quantitative blood tests to detect even very low levels of hCG. They can also do an ultrasound scan to confirm the pregnancy, check for multiples, and rule out ectopic pregnancy.
The bottom line
You can take a pregnancy test at night and expect accurate results as long as you have not urinated for at least 4 hours beforehand. However, testing your first morning urine gives the most reliable results.
If you suspect pregnancy and get a negative nighttime test, re-test first thing in the morning. Be sure to read and follow all test instructions carefully for best accuracy. See your doctor for further evaluation if you continue to get negative home tests but still think you’re pregnant.
Frequently Asked Questions
Can I take a pregnancy test at night and get an accurate result?
Yes, you can take a pregnancy test at night and get an accurate result as long as you have not urinated for at least 4 hours before taking the test. However, first morning urine tends to be the most concentrated and ideal for early pregnancy testing.
Should I use first morning urine or nighttime urine?
First morning urine is preferred for early pregnancy testing because hCG levels peak overnight. However, nighttime urine can still provide an accurate result as long as you haven’t urinated for several hours before the test.
How soon can I take a pregnancy test?
Most pregnancy tests can detect hCG levels around the time of your expected period. However, early detection tests can be accurate up to 6 days sooner. Talk to your doctor if unsure when to test.
Can certain foods or medications affect the results?
Yes, certain foods and medications can affect pregnancy test results. Large amounts of liquids can dilute the urine and cause false negatives. Some fertility, hypertension, and psychiatric medications can also alter results.
What if I get a faint line on the test?
A faint line still indicates a positive result. The line may be light if you are testing very early or your urine is diluted. Try retesting with morning urine to confirm.
References
[1] American Pregnancy Association. “Home Pregnancy Tests: Can You Trust the Results?” https://americanpregnancy.org/getting-pregnant/home-pregnancy-tests-94064/. Accessed 27 Jan. 2023.
[2] Mayo Clinic. “Pregnancy Test.” https://www.mayoclinic.org/tests-procedures/pregnancy-test/about/pac-20384775. Accessed 27 Jan. 2023.
[3] Office on Women’s Health. “Home pregnancy tests.” https://www.womenshealth.gov/a-z-topics/home-pregnancy-tests. Accessed 27 Jan. 2023.