1 month ago, I bumped my forehead against a door; I failed to put ice on it due to time constraints. The bump (about the size of a pea to a chick pea, is not going down. When I move the skin above the bump, the bump "moves with it", so it does not appear to be on the bone/skull; rather it appears to be within the skin. Will the swelling go down if I apply ice to it now, even though it is 4 weeks later? Could it be something like a subcutaneous cyst, etc.?