Chemical pregnancies are much more common than you might think. In fact, between 50% and 60% of all first-time pregnancies are thought to end in miscarriage – a large majority of which can be attributed to chemical pregnancies. The difference between a chemical pregnancy and most other forms of miscarriage is that many women don’t even realize that they have experienced one. This is because the vast majority of chemical pregnancies occur within the initial six weeks of pregnancy, when most typical pregnancy symptoms are not yet present, meaning that women is unlikely to take a pregnancy test.