About two days ago I noticed what looked like a boil or a pimple starting on the underside of my left breast. Each day it has gotten worse. This morning after my shower I looked at it and it had a small hole in the middle and darkened tissue around the edge then redness surrounding that. Now the hole is larger and drainging serosanguinous drainage and the darkened tissue looks either bruised or black, it is a hard area to look at. The entire underside of my left breast (where the sore is) is painful and it is very painful to touch or clean the actual open area. I was wondering what this might be. I tried to get into see my MD today but he is out of town, so I tried all other MD offices in my area and no one had any openings. My MD will be back latter part of next week around 1st of May. At the rate this thing has spread just today I am scared to go too long. Does anyone know what this might be? Could it just be an infected pimple? However, before it had an opening it never looked like it had any pus or fluid. It was just a hard sore, red area. I appreciate any help. Thank you.