Spot in the nipple..

Tiffany
Umm, I don't know how to explain this. I think about last week or 2 weeks ago. I had this tiny spot in my nipple where milk supposed to come out appeared out of no where.. I was not sure why. It doesn't hurt or anything just odd.. Should I be concerned? Or it's just normal? I have 2 kids that is 3 and 2 years old.