What can cause this remaining tenderness?

[Bubulinu]

About 9 weeks ago I hit my head quite hard on a sloping ceiling, as I was going to sit on a couch beneath that that same ceiling. I remember hitting my head, and also saying in my head "Oh ****!" and going to sit on the couch after. My friend who was in the other room said he heard me say "Oh ****!" - I don't remember saying it though except in my mind. There was no vomiting, and no other signs. The next few days I had a few headaches, and I went to the doctor, who checked my eyes and my neck muscles, and said that the aches were from the neck, and internal bleeding was very unlikely. After that, no more symptoms. Recently, I noticed however that if I press quite HARD on that spot where the hit happened, it hurts slightly. Not a big pain, but different than pressing the same way on the other side. It has been 9 weeks since hitting the head. Should this be something to worry about, and what could be causing such tenderness long after? It's not tender to normal touching, just to hard pressing on the spot. Thanks!