There are two types of pregnancy tests:
Both of these tests look for the presence of hCG, hormone found in
pregnancy. Many women use a urine test, or home pregnancy test (HPT),
to find out if they are pregnant. HPTs are inexpensive, are easy to
use, can be done at home, and are private. If you have a positive result
on an HPT, you need to see your health care provider right away. The
health care provider can confirm a positive HPT result with a blood
test and a pelvic exam.
There are two types of blood tests you can get from a health care provider:
- Quantitative blood test (or the beta hCG test) - This test measures
the exact amount of hCG in the blood. This means it can pick up very
small amounts of hCG, making it a very accurate test.
- Qualitative hCG blood test - This test gives a simple yes or no
answer to whether you are pregnant. It is more like a urine test in
terms of its accuracy.
Blood tests can pick up hCG earlier in a pregnancy than urine tests
can. Blood tests can tell if you are pregnant about 6 to 8 days after
you ovulate (or release an egg from an ovary). Urine tests can determine
pregnancy about 2 weeks after ovulation. Some more sensitive urine tests
can tell if you are pregnant as early as 6 days after you conceive,
or one day after you miss a menstrual period.
There are many types of home pregnancy tests, or HPTs, that can be
bought over-the-counter at drug or discount stores. Some involve collecting
your urine in a cup and dipping a stick into the urine, or putting some
of the urine into a special container with an eyedropper. Others are
done by placing a stick into your urine stream. Tests vary in how long
you have to wait for the stick or container to turn a certain color
or have a symbol on it (like a plus or a minus). All tests come with
written instructions. Most tests also have toll-free phone numbers to
call if you have any questions about how to do the test or read the
Home pregnancy tests (HPTs) are very accurate. Most brands of HPTs
say they are 97% to 99% accurate, but this can vary with actual use.
Each brand varies in how sensitive it is in picking up the pregnancy
hormone hCG. If a test is not done correctly, it will be less accurate.
And, always check the package to make sure it is not past its expiration
date - if it is, it will not be accurate. Most brands of HPTs tell users
to do the test again in a few days, no matter what the results.
If you use an HPT too early in your pregnancy, you may not have enough
of the pregnancy hormone hCG in your urine to have a positive test result.
Most HPTs will be accurate if you test yourself around the time your
period is due (about 2 weeks after you ovulate, or release an egg from
your ovary). You can get a negative test result if you are not pregnant
or if you ovulated later than you thought you did. You may also have
problems with the pregnancy, which affects the amount of hCG you have
in your urine. If your HPT is negative, test yourself again within a
few days to 1 week. If you keep getting a negative result and think
you are pregnant, talk with a health care provider right away.
Most medications, both over-the-counter and prescription drugs, including
birth control pills and antibiotics, should not affect the results of
a home pregnancy test (such as Profasi, Pregnyl or Novarel). Only those
drugs that have the pregnancy hormone hCG in them can give a false positive
test result (where the test says you are pregnant when you actually
are not). Drugs that have hCG in them can be used for treating infertility
(not being able to get pregnant). Alcohol and illegal drugs do not affect
HPT results, but you should not be using these substances if you are
trying to get pregnant.