If you’re worried that you could be pregnant, when is it time to take a pregnancy test? Does it matter when you take it?
Many assume that a pregnancy test doesn’t have to be timed to be correct, or that if they take many different kinds of tests they may get a different result. The truth is, it all comes down to timing. Taking a test too early can give you a negative result, even if you are indeed pregnant.
How Does a Home Pregnancy Test Work?
All pregnancy tests measure the levels of Human Chorionic Gonadotrophin (hCG), in your urine, which your body begins to produce at around 6 days after fertilization off the egg and gradually increases up until about 10-12 weeks of pregnancy. HCG is not a hormone found in a measurable quantity in non-pregnant women except in rare cases of cancer, or if you’ve recently had an abortion or miscarriage. This means that if HCG is found in your blood with a pregnancy test, you’re pregnant.
How Do I Take a Pregnancy Test?
Pregnancy tests vary from brand to brand, so always follow the instructions on the box. Generally, you will pee on the stick (or pee in a cup and dip the stick into the pee, it can be slightly less messy this way) and then read the results after the directed amount of time. Do not read the results after the recommended time frame, as ink bleeding could result in a false positive.
Prior to taking a home pregnancy test, make sure to check the expiration date on the packaging as this could also affect the results and accuracy of the test.
When Should I take a pregnancy test?
Pregnancy tests are the most accurate after you have missed your period. Some brands of pregnancy tests are more sensitive than others (a lower “concentration threshold) and can detect hCG at a lower amount, which is how they can sometimes get a positive result before a missed period. However, several studies have found these claims to be misleading and can produce a false negative result up to 25% of the time.
DO EXPIRED PREGNANCY TESTS WORK?
No. Expired tests are not able to test for hCG at the same level as a non-expired test, so any results from an expired test should be verified with a non-expired test. A negative result from an expired test may be wrong. A positive result could still be assumed to be positive, but would need to be confirmed with another test.
WHAT DOES A POSITIVE PREGNANCY TEST LOOK LIKE?
A positive test will look either like two lines in the test window, a plus sign, or the word “pregnant” depending on the type and brand of pregnancy test that you use.
For a test with lines, the first line that appears is the control line, and if a second line appears, even faintly, the test should be read as positive.
DOES IT MATTER IF I TAKE A PREGNANCY TEST EARLY?
Though pregnancy lasts 40 weeks, you aren’t actually pregnant the first two weeks as ovulation typically occurs on day 14 of one’s menstrual cycle.
Then, approximately 6 days after a fertilized egg attaches to the lining of the uterus, your body begins to develop the placenta, which produces the hormone human chorionic gonadotropin (HCG), which enters your bloodstream and urine. In early pregnancy, HCG levels double every two to three days. If you take the test too early, your levels will most likely be too low to detect.
Although ovulation generally occurs on day 14 of one’s cycle, the timing of ovulation can vary from person to person or month to month – and this can affect the timing of when you should take a test. For this reason, a pregnancy test will be the most accurate after your period is due and doesn’t show.
WHAT IF I HAVE IRREGULAR PERIODS?
If your periods are irregular, you will want to wait until the length of your longest cycle before you take a pregnancy test. If you don’t get periods at all or your periods are very irregular, a good rule of thumb is to wait until 3 weeks after you have had unprotected sex.
CAN I GET A FALSE NEGATIVE?
Yes. False negatives happen to 10 to 20 people in every 100 who take a test because HCG levels can vary from person to person. If your test is negative but you are experiencing symptoms of pregnancy or still believe you could be pregnant, wait two more days and take another test. If your period does not begin within the week, take another test. By then, if you are pregnant, your HCG should have doubled once again, giving you a more accurate result. If you continue to get negative results but are not having periods, consult with your doctor as there may be other underlying health issues at play.
CAN I GET A FALSE POSITIVE?
Yes…but it’s not likely. For a test to detect HCG in your urine when you are not pregnant means that either the test was defective, or something else is going on. This could mean that you are having an early ectopic miscarriage, ectopic pregnancy, problems with ovaries, or menopause. If you have a positive pregnancy test, visiting your doctor or coming to Alpha Center for a pregnancy appointment is important.
WHAT IF I HAD A POSITIVE PREGNANCY TEST AND NOW IT’S NEGATIVE?
If you had a positive pregnancy test only to have a negative test a few days later, it’s possible that you experienced a chemical pregnancy. Essentially, there was fertilization and your body began to produce hCG, but the pregnancy did not continue for any number of reasons. Biochemical pregnancy has also been defined as a pregnancy loss that was too early for any other symptoms aside from elevated hCG levels.
DO EARLY PREGNANCY TESTS WORK?
Some pregnancy tests will advertise working up to 6 days before your missed period. It all depends on how your body is producing HCG. For some people, these tests will work and for others, the test can show a false negative. The most accurate result will happen after you miss your period.
DOES THE BRAND OF PREGNANCY TEST MATTER?
Generally, no. Most at-home pregnancy tests measure the HCG in your urine. If you follow the instructions on the test, you should get an accurate result. Alpha Center offers free pregnancy testing during our pregnancy appointments. Request an appointment here.
I TOOK THE TEST, AND IT’S POSITIVE. NOW WHAT?
If you are unexpectedly pregnant, it can be a lot to process. You might be feeling scared, confused, or simply overwhelmed. At Alpha Center in Fort Collins, we know how important it is to have results you can trust. We offer free and confidential pregnancy testing to anyone who thinks they may be facing an unplanned pregnancy, and we offer a non-judgmental space to explore your options and ask questions. Request an appointment.
Author: Kristen Long, Alpha Center. Last updated July 2024.
Sources:
- https://www.mayoclinic.org/healthy-lifestyle/getting-pregnant/in-depth/home-pregnancy-tests/art-20047940
- https://www.nhs.uk/pregnancy/trying-for-a-baby/doing-a-pregnancy-test/
- https://www.plannedparenthood.org/learn/pregnancy/pregnancy-tests
- https://www.mayoclinic.org/healthy-lifestyle/pregnancy-week-by-week/in-depth/prenatal-care/art-20045302′
- https://www.clearblue.com/pregnancy-tests/do-pregnancy-tests-expire
- https://helloclue.com/articles/trying-to-conceive/how-soon-can-i-take-a-pregnancy-test
- Johnson, S., Cushion, M., Bond, S., Godbert, S., & Pike, J. (2015). Comparison of analytical sensitivity and women’s interpretation of home pregnancy tests. Clinical chemistry and laboratory medicine, 53(3), 391–402. https://doi.org/10.1515/cclm-2014-0643
- Annan, J., Gudi, A., Bhide, P., Shah, A., & Homburg, R. (2013). Biochemical Pregnancy During Assisted Conception: A Little Bit Pregnant. Journal Of Clinical Medicine Research, 5(4), 269-274.
- https://doi.org/10.1016/j.beem.2013.10.005
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