New Crown 3 refers to the 3rd dose of the New Crown vaccine, and breast pain after the 3rd dose of the New Crown vaccine is not related to the New Crown vaccine in any way. It can be considered to be related to traumatic impaction, premenstrual syndrome and breast enlargement. 1. Traumatic impaction: If your breasts are impacted by an external force, it will cause pain in your breasts. 2. Premenstrual syndrome: the hormone level in the body will change before menstruation, which will cause breast pain, lumbago, abdominal pain and other symptoms. 3. Breast enlargement: Breast enlargement is common in young and middle-aged women, mostly cyclical changes, pain before menstruation, pain relief after menstruation, if the symptoms are serious can be taken under the guidance of the doctor, such as small gold pills and other drugs treatment. Breast pain can also be caused by mastitis, breast tumors and other causes, it is recommended to go to the hospital to do relevant examinations to clarify the causes of the disease, and then targeted treatment. The use of drugs should be under the guidance of a doctor.