About 26 percent of all pregnancies end in miscarriage, which is defined as the loss of pregnancy at 20 weeks gestation or less. Sometimes, a miscarriage can occur very early in pregnancy, before a fetus even starts to develop. This type of miscarriage is called a chemical pregnancy, or biochemical pregnancy.

Dr. Lisa Becht, a board-certified reproductive endocrinologist at HRC Fertility Newport Beach and Mission Viejo explains that the early symptoms of a chemical pregnancy (before any bleeding or cramping occur) are the same as a clinical pregnancy (which is when the fetus develops). These symptoms can include a missed period, breast tenderness, nausea, and fatigue.

“A woman may experience bleeding and cramping within a few days or the week of getting a positive pregnancy test, or quickly after she gets the positive test she then gets her period, maybe heavier than usual or just normal,” says Dr. Becht. Since the pregnancy stops developing so early, some women may never even realize they had a chemical pregnancy.

If you are experiencing a lot of pain or bleeding due to a chemical pregnancy, it is important that you consult with your doctor right away. To learn more about chemical pregnancies, read the article in its entirety here.