Definitely agree with the suggestion to see your doctor.

In addition to that, may I ask how much caffeine you consume each day? If it's a lot, you may want to try cutting back as much as possible to see if that makes any difference. I used to have frequent breast pain and asked my GYN what might be causing it. She said the two main culprits are hormones and caffeine. I eliminated caffeine and now only get breast pain at certain times of the month (and even then it's much less severe). Mine was generalized breast pain, however. Nothing in the nipple area. Still might be worth considering in your case.