White dots on nipples?

I was taking a shower the other day and my boobs started hurting a little. The water doesn’t come out really hard, it actually sprays out soft. After getting out of the shower I looked down and saw white dots just barely sticking out of my nipples. While they don’t look like that anymore they still hurt and have little bumps on it. Nothing abnormal looking but I just thought this was weird. Any thoughts on what this could be?