Bump on Puppy's Head?! :(

[courtenay.m]

Hi everyone!
Just the other day, I noticed a little bump on the top of my puppy's head. He's 8 months old and it's just recently appeared. It hasn't gotten any bigger or smaller within the last few days and I'm just being told that it's a pimple or something along those lines. Since it's not changing in size and is very hard to the touch I thought that perhaps the advise I had gotten was wrong and thought I'd throw it out to you guys. It doesn't hurt him when it's touched and there's a little bit of hard blood that surrounds the base of the bump as well. I'm taking him in to the vet at the end of the week to be fixed so I'm going to ask them then but does anyone else have any suggestions in the meantime?

Here is the only picture I could get him to stay still long enough for me to take: