There are two types of pregnancy tests; one uses a urine sample, the other a sample of blood. Both tests detect the presence of a hormone called human chorionic gonadotropin (hCG). This hormone is produced by the placenta shortly after the embryo attaches to the uterine lining and builds up rapidly in your body in the first few days of pregnancy.
It is this rapid shift in hormones that triggers most of your pregnancy symptoms.
Urine tests can be performed in two different ways and these can be performed at home or in a clinic. One way involves collecting your urine in a cup and dipping a stick into the urine or putting urine into a special container with an eyedropper. Another option involves placing a stick into your urine stream and catching your urine in midstream.
Tests vary in how long you have to wait to get a result. You will be looking for a change in color, a line, or a symbol (like a plus or minus).
How accurate are urine tests?
Urine tests or home pregnancy tests are around 97% accurate when done correctly.
There are two types of blood tests. A quantitative blood test measures the exact amount of hCG in the blood, and a qualitative hCG blood test gives a simple yes or no answer to whether you are pregnant or not.
Advantages of having a blood test done:
Can detect a pregnancy earlier than a urine test at about 7-12 days from possible conception (but if a negative result is received, a test should be repeated if a period is missed.)
Can measure the concentration of hCG hormone in your blood (this is useful information for your healthcare provider in tracking certain problems in pregnancy)
Disadvantages to having a blood test done:
More expensive than a urine test (price depends on cost of doctor’s visit and lab fees)
Takes longer to get result
Must be done in a doctor’s office