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 chorionicgonadotropin (hCG) in a sample of urine or blood. This hormone HCG is producedby the placenta and is found in pregnantwomen. The amount of hCG produced during early pregnancy doubles every2-3 days and peaks at 7-10 weeks. Youcan be tested for pregnancy with an over-the-counter pregnancy testor in your healthcare provider's office.
How Soon After Conception Will a Home Pregnancy Test Work?Some, but not all, home pregnancy tests can detect pregnancy as early as 1 day after a missed menstrual period.Most home pregnancy tests are very accurate when done about a week afteryour 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, whileothers ask that you urinate in a cup and then place a small sample intoa 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 withdifferent tests as well. For example, some show a red plus or minus sign ina window, others show pink or blue lines on a test strip, whileothers 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 manufacturersclaim to have a 99% accuracy rate, but inaccurate results may bemore frequent. This is because of improper use of the test, using the test afterits expiration date, exposure of the test to the sun, and otherfactors. 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.Afterconception, a woman produces a minimal amount of hCG. Not all tests are strong enough to pick up the amount of hCG hormone present the firsttime. Later tests may be positive. Whatever theresult or the brand used, most manufacturers recommend repeatingthe 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 (falsenegative) if you take the test too early after conception, before hCG levels aresignificant.
- If you are taking medications that has hCG in them, you may get a positive test even if you are not pregnant (falsepositive).
How Are Pregnancy Tests Conducted in a Medical Office?Either a urine test or bloodtest is available at your healthcare provider's office or a familyplanning clinic. For the urine test, a urinesample is taken, usually first thing in the morning.A blood hCG testinvolves taking a sample of blood from a vein in the arm. A bloodtest 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 thesepregnancy tests may be available the same day they areadministered.If your test is positive, make sure you follow up with your healthcare provider right away. You cannot start prenatal care too soon.
Family Doctor—American Academy of Family Physicians
Office on Women's Health
Women's Health Matters
Knowing if you're pregnant. Office on 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.
First trimester: Pregnancy testing. American Association for Clinical Chemistry Lab Tests Online website. Available at: http://labtestsonline.org/understanding/wellness/pregnancy/first-trimester/hcg. Updated June 4, 2014. Accessed December 9, 2014.
Routine prenatal care. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed. Updated December 4, 2014. Accessed December 9, 2014.
- Reviewer: Michael Woods, MD
- Review Date: 12/2014
- Update Date: 12/09/2014