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.
There are different types of urine tests, and these can be performed at home or in a clinic. The first type of test involves collecting your urine in a cup and dipping a stick into the urine, or putting urine into a special container with an eyedropper.
A second type of test 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). A new digital pregnancy test offered by Clearblue Easy makes reading your results simple: the window will either show the words "not pregnant" or "pregnant". You can also get recommended midstream urine tests online: Order my pregnancy test
All tests come with instructions, and it is important that you follow these instructions to get an accurate reading.
Most doctors recommend that you wait until the first day of your missed period before taking a urine pregnancy test. This is usually about two weeks after conception. However, some tests are more sensitive than others and can be taken earlier.
you get a negative result and still have symptoms of pregnancy (missed period, nausea, breast tenderness and fatigue), wait a week and take another test or contact your doctor so you can have a blood test done.
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