About a month ago, I found a lump on the right side of my head on the top of my skull. Its not even with the other side of my head because there's no other lump on the other side. It doesn't hurt when I put pressure on it. Its just hard. I don't get headaches or feel any other kind of pain. I'm not sure what it is, or if it even is anything. Could it be just the way my skull is shaped? Or could it be something else? Should I worry? Please let me know as soon as possible! Thanks!