There are two types of pregnancy tests available. One uses a blood sample to test for pregnancy, and the other uses a sample of urine and can be done at home.
Both types of tests determine pregnancy by testing for a hormone called hCG (human chorionic gonadotropin). This hormone starts to produce the placenta soon after the embryo attaches to the lining of the uterus.
The presence of hCG means the woman is pregnant. The rapid production and increasing amount of this hormone is what tends to trigger pregnancy symptoms.
Urine tests to determine pregnancy
Pregnancy tests that use a urine sample are available over-the-counter. They are generally inexpensive ($7 to $20) and easy to use. They are 97 percent accurate if used correctly.
Urine pregnancy tests can also be performed by your doctor.
Some urine tests require you to collect urine in a cup, and then dip a testing stick into the urine. With other urine tests, you simply place the testing stick into your urine stream directly.
Testing time varies by test, but you will have to wait a few minutes to get a result. Some tests display a color change, while others display a symbol (a plus or minus sign is common). Some tests show the words “pregnant” or “not pregnant.”
Be sure to follow the instructions that come with the test carefully in order to obtain a correct reading.
When to take a urine test
It is best to wait until at least the first day of your missed period to take a urine test. Some tests are more sensitive and can be taken earlier. Be sure to follow the instructions on the packaging.
If you receive a negative result, but have symptoms of pregnancy such as breast tenderness, nausea or a missed period, wait another week and take another test or contact your health provider for a blood test.
Blood tests to determine pregnancy
A blood test, which is performed at your doctor’s office, can also determine if you are pregnant. There are two kinds of blood tests. One provides a simple yes or no answer to whether or not you are pregnant.
The other type of blood test measures the actual amount of hCG (pregnancy hormone in your blood). This type of test is beneficial if your medical provider has concerns or is tracking problems in your pregnancy.
When to have a blood test
Blood tests can determine pregnancy within 7 to 12 days after conception, but must be performed by a medical health provider. Results take longer than the over-the-counter urine tests.