I'm 18 and whenever im on my menstural cycle and a week before it my breast always are sore and it hurts. Is this normal? This started a year ago

Mastaglia. Breast tenderness is called mastalgia, and it is normal before or during periods. It is due to the abrupt changes in hormone levels that are part of the normal menstrual cycle. Some women experience it intensely, while other women don't experience it at all. It is normal. If associated with other severe symptoms, you may have pms (premenstrual syndrome), which is treatable.