Home and Clinic Pregnancy Tests
Do you think you may be pregnant? Here are a few tips about your pregnancy testing options...
What Is a Pregnancy Test?
Pregnancy tests detect a hormone called human chorionic
gonadotropin (hCG) in a sample of urine or blood. This hormone HCG is produced
by the placenta and is found in pregnant
women. The amount of hCG produced during early pregnancy doubles every
two or three days and peaks at 7-10 weeks. You
can be tested for pregnancy with an over-the-counter pregnancy test
or in your healthcare provider's office.
How Soon After Conception Will a Home Pregnancy Test Work?
Some home pregnancy tests can detect pregnancy as early as one day after a missed menstrual period, although not all pregnancies will be picked up this early.
Most home pregnancy tests are very accurate when done about a week after
your first missed menstrual period.
How Are Pregnancy Tests Done at Home?
There are several different types of home pregnancy tests that are readily available at your local drug store. Because there are many brands, it is important to follow the directions on the individual package carefully.
Some tests require that you urinate directly on a stick, while
others ask that you urinate in a cup and then place a small sample into
a testing well with a dropper. The results can be as fast as a few minutes or as long as a several hours. Keep in mind that results are displayed differently with
different tests as well. For example, some show a red plus or minus sign in
a window, others show pink or blue lines on a test strip, while
others change the color of a urine sample.
Once you get a result, you may begin to question the test's accuracy.
How Accurate Are Pregnancy Tests?
Home pregnancy tests are not 100% accurate. Many manufacturers
claim to have a 99% accuracy rate, but inaccurate results may be
more frequent. This is because of improper use of the test, using the test after
its expiration date, exposure of the test to the sun, and other
factors. Again, make sure to follow the directions of your particular test exactly as you are supposed to. This should help make the test more accurate.
conception, a woman produces a minimal amount of hCG. Not all tests are strong enough to pick up the amount of hCG hormone present the first
time. Later tests may be positive. Whatever the
result or the brand used, most manufacturers recommend repeating
the process several days later to confirm the results.
Other potential problems include:
- It is possible that you may get a negative test even if you are pregnant (false
negative) if you take the test too early after conception, before hCG levels are
- If you are taking medications that has hCG in them, you may get a positive test even if you are not pregnant (false
How Are Pregnancy Tests Conducted in a Medical Office?
Either a urine test or blood
test is available at your healthcare provider's office or a family
planning clinic. For the urine test, a urine
sample is taken, usually first thing in the morning.
A blood hCG test
involves taking a sample of blood from a vein in the arm. A blood
test may be ordered to measure how much hCG is in the blood. The blood test can detect a pregnancy earlier than the urine test. Results of these
pregnancy tests may be available the same day they are
If your test is positive, make sure you follow up with your healthcare provider right away. You cannot start prenatal care too soon.
American Academy of Family Physicians
Women's Health—US Department of Health and Human Services
Women's Health Matters
Knowing if You're Pregnant. United States Health and Human Services Women's Health website. Available at: http://womenshealth.gov/pregnancy/before-you-get-pregnant/knowing-if-pregnant.html. Updated September 27, 2010. Accessed December 11, 2012.
Pregnancy testing. EBSCO DynaMed website. Available at:
http://www.ebscohost.com/dynamed. Updated November 2, 2012. Accessed December 11, 2012.
Pregnancy Test Fact Sheet. United States Health and Human Services Women's Health website. Available at: http://www.womenshealth.gov/publications/our-publications/fact-sheet/pregnancy-tests.html. Updated July 16, 2012. Accessed December 11, 2012.