I just recently noticed that I have a really small scab on the center of my nipple, (I'm a 17yr old girl) and it's about the size of a pin needle, maybe smaller. It doesn't hurt to touch but it does bleed a little when I picked at it. My family has no history of breast cancer, and I think it just formed today. And I'm on my period if that would change anything? Does anyone have any advice on what it may be caused from?