Strange bump seemingly appeared overnight?

Jo • ShySlytherin0427

So I just got out of he shower, and while drying off I noticed this strange bump on my left breast, I’m fairly certain it wasn’t there last night, and I’m concerned. I normally get a lot of heat pimples in this kind of spot so that’s what I thought it was, just a really bad one, but when I scratched at it it did nothing but get red a mind bleed a little bit. Anyone know what it could possibly be?

Update: It seems to be right about/slightly above my bra line