dear user thanks for contact HCM first i would like to tell you that pain in the breast is common problem for women and it has some causes for that first cause and very common is that it may occur due to hormonal effects in menstrual cycle..... and always pain is most common in the week or so before your menstrual cycle and may end once menstruation begins. Some other causes such as mastitis may cause a more severe pain and need clinical examination also Costochondritis may cause breast pain and need antiinflammatory drugs for treatment also there is what is called Fibrocystic breast changes may occur and cause pain Breast cancer may cause pain also but there will be some other findings with it and you neednot to worry of that....breast pain doesnot mean you are pregnant but it indicates hormonal changes when the period is near so dont worry of that wish you healthy life