During the first month of pregnancy, some women may experience breast swelling and pain, which is a normal physiological phenomenon. The main reason for breast swelling and pain after pregnancy is that the progesterone secreted by the ovaries starts to increase, and progesterone promotes the growth of breast follicles, so women who feel that their whole breasts are enlarged and their breasts are swollen and painful can be relieved by wearing loose-fitting underwear, massage and other ways. In addition, if the swelling and pain of the breasts is obvious or if you can touch the nodules, you need to go to the hospital for breast ultrasound to rule out the existence of breast diseases such as breast hyperplasia or breast nodules, so that you can give the appropriate examinations and treatments as soon as possible. During the first month of pregnancy, some women may experience breast swelling and pain, while others may experience morning sickness, vomiting, frequent urination and fatigue, which are also normal.