We often say chest pain generally refers to breast pain, pre-pregnancy chest pain is not everyone has, this is an individual difference, pre-pregnancy causes chest pain may be related to estrogen growth, breast disease. 1. Estrogen growth: two or three months after diagnosis of pregnancy due to the rapid growth of estrogen and progesterone in the body, easily caused by the expansion of breast blood vessels, there may be a slight swelling and pain, in addition, there will also be a Montgomery’s nodule, there is no other obvious discomfort can not be dealt with, is a normal physiological phenomenon. 2. Possibility of breast-related diseases: If the pain is obvious, persistent or accompanied by localized lumps, etc., further examination should be carried out to exclude breast hyperplasia, breast nodules, breast fibroids, breast cancer and other abnormalities. Some pregnant women do not have obvious chest pain before pregnancy, which needs to be combined with the history of menopause and specific tests to determine whether they are pregnant. It is recommended to go to the hospital to do a blood HCG test, uterine adnexa ultrasound, breast ultrasound, according to the specific results of the examination under the guidance of the doctor for symptomatic treatment.