Recently I have found a tiny little spot on my right nipple. It's never been sore, itchy or painful apart from last night when I must have rubbed it too hard so it was very painful from the friction. It's not an ulcer or crusty spot, it's more like a little piece of hard skin that has grown over the nipple. It's not red either, just the same colour as the rest of my nipple. I'm not pregnant or breastfeeding but could it be a milk duct blockage or pimple? I also have some dried milky discharge around it but that has always been a normal thing for me on both nipples. I had my breasts checked not long ago and everything was fine but I'm still starting to get really worried, please can anyone help??