How Does a Pregnancy Test Work?

If you are experiencing pregnancy symptoms or have taken a pregnancy test, you may be wondering how a pregnancy test works.

In other words, how do you know that you are pregnant?

When you have missed a period, you should take a pregnancy test, even if you are not experiencing other symptoms.

Whether you take a blood test or urine pregnancy test, what you are being tested for is the presence of hCG.

What is hCG?

Human chorionic gonadotrophin (hCG) is often referred to as the pregnancy hormone. hCG is produced by the placenta. It is the presence of hCG that signals the body the body to produce more estrogen and progesterone. These three hormones thicken the uterine lining and stop the release of eggs (which means no period!).

Both the urine and blood test will detect the hCG hormone.

Can a urine pregnancy test detect hCG? 

Yes, a urine pregnancy test can detect hCG levels as early as 12 days after conception.

Should I have my hCG levels checked?

It is not common for a pregnant woman's hCG levels to be checked, however, in some cases your healthcare provider may want to check your levels.

This is why it is important to see an OB when you find out that you are pregnant.

When is the best time to take a pregnancy test?

If you have missed your menstrual period, you should take a pregnancy test.

While there are early detection pregnancy tests available now, at PRC of Tracy, we still recommend waiting for a missed period in order to avoid a false-negative test in the event that it is too soon to detect the pregnancy hormone.

If you are taking an at-home pregnancy test, we recommend taking it in the morning for the most accurate result.

Another factor that might contribute to a false-negative pregnancy test is reading the result too soon.

Reading your pregnancy test result too soon might result in a negative result even though you are pregnant.  

Make sure you wait the full amount of time according to the instructions on your at-home pregnancy test.

If you get a negative result but still have symptoms, take a test again.

We offer free pregnancy tests at our center. Contact us to make an appointment and get your pregnancy test.


Sources for this post:

Mayo Clinic
Cleveland Clinic
American Pregnancy Association