cluster of small bumps on the back of my upper thigh?

I have a cluster of small blister like bumps on the back of my upper thigh, about three inches below my butt. I noticed them about five days ago and there were only three then, they've multiplied to eight now. They only itch when I touch them, and they don't hurt but I get a sore feeling when I touch them. I really don't know what it is, I realty don't want to go to my doctor. Advice anyone?