If you are pregnant, you will not have a period. Because after pregnancy there is already a fetus inside the uterus, the lining of the uterus will no longer undergo cyclic changes, and the ovaries will no longer ovulate. Therefore, during pregnancy, if there is brown blood, it is definitely not menstruation, this situation, usually indicates that there may be a case of pre-miscarriage. In addition, if the placenta of the pregnant woman is not in the normal position, there is a low placenta or placenta praevia, it is also prone to the appearance of this brown blood. If you have brown blood during pregnancy, you should go for ultrasound in time to find out the development of the fetus and the position of the placenta, and at the same time, you should pay attention to rest, use some medicines to protect the fetus appropriately, and need to consider hospitalization for fertility preservation treatment if necessary.