I Was Using A Rock As A Hammer And Hit

I was using a rock as a hammer and hit myself in the forehead. I had a big knot for a few days and the swelling is down
Today i noticed there is a very soft dent about the size of my fingertip that i can push on until the skin is tight. Could I have punched a hole in my skull? Its painful and I have had a headache but I have frequent migraines before injury. I did hit myself hard with a pointy end and saw stars.