How do pregnancy tests work, and how accurate are they?

According to the Cleveland Clinic, there are two types of pregnancy tests available: urine pregnancy tests and blood pregnancy tests. Both tests measure the same hormone in the body: Human Chorionic Gonadotropin, or HCG.

As soon as a fertilized egg implants into the uterus, formation of the placenta begins, and this process is what produces HCG. The amount of HCG in the body doubles every 2-3 days during early pregnancy. 

Urine Tests

Urine pregnancy tests are available over the counter without a prescription and are estimated to be about  99% accurate when they are used exactly as directed on the package. Reading the test too soon or leaving it out for too long can give inaccurate results, so it is important to follow the directions on the package carefully.

HCG can be detected in urine starting at 10-14 days after conception takes place, which is usually around the time a woman will notice a missed period. It is usually recommended to take the test with the first urination of the morning since HCG levels will be most concentrated then.

It is recommended that a woman wait until missing a period before taking an at-home urine pregnancy test to ensure accurate results.

Blood Tests

According to the American Pregnancy Association, blood pregnancy tests are most often performed in a healthcare provider’s office and involve a patient having blood drawn and tested for HCG.

The blood test is more sensitive than a urine test because HCG levels in blood can be detected as soon as 7-12 days after conception. A qualitative blood test is like a urine pregnancy test in that it only answers the question Am I pregnant?. 

A quantitative blood pregnancy test measures exactly how much HCG is present in the blood. This can be important to detect if HCG levels are rising or falling in the body.

Keim Centers is here to support you

Navigating this situation can feel overwhelming, but you don’t have to go through it alone. The Keim Centers are here to answer any questions you have and discuss all your options in a confidential and non-judgmental environment.

We have 5 locations across Virginia so that you can visit us at a location that is convenient for you. We also offer same-day and next-day appointments.

Please don’t hesitate to reach out to The Keim Centers. Your health and well-being are our top priorities.