So three days ago I was walking a lot in the sun, it was really hot out and my underwear started to chafe the area where my private area and my thigh meet. The next day I felt a very painful pimple under the skin and left it alone for a while. Today it was really bothering me while I was walking and I go to the bathroom to look and there's a big zit type looking thing causing the pain. Naturally I try to pop it, after much effort it finally burst but more blood came out than anything and the head was a blackish color, like a blood blister. I popped it around 2 in the afternoon, it's 1239 and it's still filled with stuff, the head is black and the surrounding area of the head looks bruised, probably due to me trying to squeeze everything out during the day. Is this just caused from the chafing? I had just shaved the area the night before, if that makes a difference. PLEASE RESPOND ASAP.