There are several possibilities: first, consider suffering from breast enlargement, the most basic symptoms are pain, lumps in the breast, and sometimes fluid overflow, especially before the menstruation will be more intense, and the pain will be relieved after the end of menstruation; second, consider suffering from acute mastitis, symptoms often occur in women who are breastfeeding for the first time, due to the blockage of milk. The typical symptoms are redness and swelling of the local skin of the breast, pain when touched, and purulent inflammation if left untreated; thirdly, pain caused by breast cancer or normal physiological reaction after pregnancy or sexual life, if the pain increases or is accompanied by other abnormal reactions, it is best to seek medical attention.