When you begin to experience pregnancy symptoms, you will likely want to take a pregnancy test to confirm whether or not you ar pregnant. There are two basic types of pregnancy tests: blood and urine. Home tests are exclusively urine tests, only a doctor can perform a blood test for pregnancy.
How Urine Tests Work
When a fertilized egg implants in the uterine wall, it starts to secrete the pregnancy hormone human chorionic gonadotrophin (HCG). This is why it is recommended that you wait until the first day of your missed period, about two weeks after conception, to take a home pregnancy test.
Urine tests use monoclonal antibodies - manmade molecules used in many laboratory tests – to test for HCG. Home pregnancy sticks have two lines: one is a control line which you will see whether you are pregnant or not, the other line contains the monoclonal antibodies. If there is HCG present in your urine, when it soaks the stick the HCG will react with the monoclonal antibodies, causing a color change that will make the second line appear. Depending on the amount of HCG in the urine, the color of the line will vary in intensity.
How Blood Tests Work
There are two types of blood tests that your doctor can give you:
- Qualitative HCG Test:
This blood test is performed in a laboratory. It only measures the presence or absence of HCG in the blood so it will only give a \"yes, you are pregnant\" or \"no, you are not\" answer.
- Quantitative HCG Test
Also performed in a lab, this test, sometimes called the Beta HCG blood test, measures the amount of HCG in the blood. It can detect even low levels of HCG, possibly giving a positive sooner.
Getting Accurate Results
Make sure you read all of the instructions that come with your home pregnancy test carefully. Also, take note of the test reading time given in the test instructions. Certain tests could give a false reading if they’re read too early or too late. A common mistake that women make when reading home pregnancy tests is waiting too long. This could result in a line appearing that could be read as a positive result, but is actually an evaporation line created as the urine on the test dries.