Menstruation is a monthly bleeding from the genital tract in women, which is the rejected tissue of the inner lining of the uterus - the endometrium. Menstruation occurs when the egg is not fertilized. But if the embryo is formed, it attaches to the endometrium, and its expected monthly detachment does not occur. Therefore, any blood-containing vaginal discharge during pregnancy is called “obstetric bleeding”1. Some of them are harmless, others are very dangerous. These are not periods. This means that every expectant mother must learn that under no circumstances should bloody discharge from the genital tract be ignored during pregnancy. Many of them are a sign of pathologies that significantly increase the risk of miscarriage and premature birth1. Therefore, report any bleeding to your doctor immediately!