Last night, I was sitting watching TV with headphones on. Then, I happened to scratch my head, and I noticed a bump on the back of my head. It is located near my left ear, above my neck. It is in an area covered by hair. It kind of hurts when left alone, just a little, almost unnoticable. When I apply pressure it hurts more. I have no idea what caused it. I'm hoping it's a bug bite. Any help?