I don t usually get breast pain for periods and I just had my period. Then the other day I started to get this severe pain in my breast, like a bruise or a pulled muscle. Just aching all the time. It is worse when I am laying down, but it is constant. I am 24 years old, good health. I don t have huge breasts and I am a healthy weight, 5 8 and 134 pounds. The pain feels like it stretches from my nipple to my ribs and over to my armpit. It is only in my left breast. My questions are, do you think it could be an infection or phlebitis or costochondritis? Ibprofen seems like it makes it better. Another question, should I go to urgent care tomorrow or try and wait till next week at the doctor. I am in so much pain, which is why I am considering urgent care.