There are two possibilities when breast pain occurs half a month before menstruation: first, there are breast diseases, such as breast hyperplasia, breast fibroids, breast malignant lesions, etc. The most common is breast hyperplasia, which is a benign lesion that many women in their reproductive years have, mainly due to poorly functioning breast ducts. The symptoms will be relieved gradually after the menstrual flow, and the pain will disappear after the menstruation is completely clean. Secondly, we need to consider pregnancy. After pregnancy, women are affected by hormone levels that lead to breast development and breast enlargement, and many women experience breast pain during early pregnancy. If you have breast tenderness and your period does not come on time, you need to take a pregnancy test in time.