Few things are as life-altering as becoming pregnant. When a woman thinks that she may be pregnant, the worst part is having to wait to find out for sure. Today, there’s an entire industry built around pregnancy tests. These tests differ in how they work, as well as in the sensitivity and accuracy of their readings. This has led many women to ask questions like, ‘how accurate are pregnancy tests’, ‘can I trust the results’, and ‘how early can you detect pregnancy with an at-home test’? Let’s first look at how pregnancy tests work before addressing their accuracy and how early you can test for pregnancy. How Pregnancy Tests Work Even the earliest pregnancy tests worked by analyzing hormone levels. In particular, these tests detected whether or not human chorionic gonadotropin (hCG) was present. This type of test is still used today and operates in the same fashion. When a fertilized egg attaches to the uterus, the developing placenta causes hCG to be released. The hormone t