Your Guide to Pregnancy Tests

"Am I pregnant?" is one of the most important questions a woman can ask. If you think you are pregnant, you want to get the correct answer quickly.

Today's home pregnancy tests are virtually foolproof and almost as accurate as those given at the doctor's office. But there are some important issues to consider when deciding what kind of pregnancy test is right for you.

Home Pregnancy Tests

According to most manufacturers, home pregnancy tests are about 99% effective when used as instructed. That's about the same accuracy rate as most urine pregnancy tests performed in a doctor's office. The tests are available in most pharmacies and do not require a prescription.

One advantage of the tests is that they allow you greater privacy and flexibility in finding out the results. You can take them anywhere there's a bathroom, and they generally take only a few minutes.

home pregnancy tests consist of placing a drop of urine on a prepared chemical strip or placing the strip in the urine stream. The strip is designed to detect a pregnancy hormone called human chorionic gonadotropin (hCG).

hCG is released into the body by the placenta when a woman is pregnant. This hormone is also responsible for causing some of the initial symptoms of pregnancy such as breast tenderness and nausea.

hCG levels usually become detectable in the urine about 10 days after conception. If you take a urine pregnancy test less than 10 days after conception, a home pregnancy test may give a false negative response. This means it will show you are not pregnant when you in fact are.

Experts say women should wait 5-10 days after their period is officially late before taking the tests to ensure accuracy. If the test is negative, wait a few more days. If menstruation still doesn't begin, take the test again and see your doctor if you have more questions. Not all pregnancy tests are identical and some are more sensitive than others, detecting lower levels of hCG. The smaller the amount of hCG the test measures, the earlier it can detect your pregnancy.

Here are some tips to follow when taking a home pregnancy test:

• Use your first morning urine when possible (when hCG levels are most easily detected). If not, make sure your urine had been in your bladder for at least 4 hours.
• Do not drink excessive amounts of fluids before the test to increase the volume of urine. This could dilute the hCG levels.
• Read the directions included in the test thoroughly before starting the test and follow every step precisely.
• Some fertility drugs or other medications may interfere with the test results. Check the package labeling for information.

In addition, if there is a problem with the pregnancy, such as an ectopic pregnancy (when the fertilized egg settles in the fallopian tube instead of the uterus), hCG levels may be low and non-detectable by a home pregnancy test. See your doctor if you are unsure about the test's results.