There are two types of pregnancy tests. One is a urine test; the other is a blood test. Both measure the hormones of pregnancy, hCG.
Early in a pregnancy, the hormones of pregnancy hCG double every 48 hours. This allows your doctor to determine very early on if you have these hormones in your blood or urine.
Blood tests can be done at your doctor’s office. Blood test measure the specific amount of pregnancy hormones present on a woman’s body. There are two different blood tests that can be done.
A qualitative hCG determines the level of pregnancy hormones in the blood. This gives a measure of how pregnant a woman is. The result, much like an EPT provides positive or negative results only. Blood testing is usually more accurate than urine pregnancy tests.
A quantitative hCG determines the level of pregnancy hormones in the blood. These are sometimes used to measure the success of the termination. These tests are very sensitive and accurate. They can measure the hCG within several days after ovulation.
EPT (Early Pregnancy Tests) can be purchased over the counter. These tests determine if there is hCG in a woman’s urine. These tests vary in accuracy and sensitivity. Most tests come with specific instructions as to how to do the test, and how to read the response. Generally a woman collects her urine in a cup and adds a few drops to a testing device. Some other tests require that the test strip be dipped into the cup of urine. If you purchase an over the counter test in your drug store or discount store, check the expiration date before you buy. These tests are generally fairly accurate and detect hCG within 2 weeks after ovulation.
The EPT tests done in your doctor’s office are usually more sensitive and accurate. These tests provide a clinical measure of accuracy. They are usually no more expensive than an over the counter test, but provide greater accuracy.
After an abortion, a woman may still see positive results in an EPT for several weeks. This is because the hormones of pregnancy leave the body slowly over several weeks at a time. A positive pregnancy test a week or two after an abortion does not mean that you are still pregnant. It is probably reflecting this slow decline in hormone levels and is to be expected.