My right nipple hurts. A few times a day it becomes hard, as in really hard, currently for example it's so hard I can feel the shape (as a "bump") through my clothes and I'm wearing a bra, a tshirt, a sweater and a vest. It'll hurt really badly, then after a few minutes it'll go soft again and the pain will disappear for the most part. There's no discoloration and the nipple doesn't feel warm. I've never had this before. I'm not pregnant and about 30 years too young for menopause. Anyone an idea what this could be?