I Am Concerned About My Health Because I Have A

I am concerned about my health because I have a small bump on the back of my head, slightly to the left. I can only feel it if I feel around the area for it. I can point out exactly where it is. This bump isn't keeping me awake at night or anything but I just would like to know what it is. I'm 15 and just would like some information, not any kind of treatment. I do not think it is cancer. If anything, it could just be a blood clot. Please help.