Pregnancy could be one cause
Pregnancy can cause it. Nipple tenderness is usually the first sign that i am pregnant. I have never felt it any other time. go get a pregnancy test. good luck!
Hi Shanda - I'm having this problem CURRENTLY! I've always had normal & regular periods with very little PMS symptoms. Please let me know if you get an answer on this one or if something other than possible pregnancy could be the culprit. Thanks! :)