First, How Do Pregnancy Tests Work?
Pregnancy tests are specifically designed to tell if either your blood or urine contains a hormone, human chorionic gonadotropin (or hCG), which your body produces while you’re pregnant, after the fertilized egg finished embedding itself to the endometrium.
There are two types of pregnancy tests:
- Qualitative tests: These tests simply check to see if hCG is present in your urine, regardless of the amount. If you want to know if you’re pregnant or not, a qualitative hCG test will give you the answer – “yes” or “no.” They can be used to detect pregnancy as early as 10 days after your missed period; some can tell if you’re pregnant sooner than 10 days.
- Quantitative tests: Quantitative tests won’t simply tell you if you’re pregnant or not. Instead, they measure the amount of hCG in your urine. Usually, these tests can detect even very low levels of hCG, sometimes as low as 10mIU/ml. You can use a quantitative hCG test for more than just test for pregnancy. Since they measure the amount of the pregnancy hormone in your urine, they’re good at detecting potential issues during the course of pregnancy (e.g. before a miscarriage, hCG levels drop significantly).