Milk Blister???

☆Veed☆
I may have a milk blister. It hurts like a pimple the only weird thing about this is that I'm not pregnant (that I know of) and haven't breastfed in almost 5 years. Could this mean I'm pregnant? I'm 10 days away from my period so It's too early to test. Please help??! Any advice? Has anyone had this?