I play for a club soccer team, and I can always expect a headache after playing in a game. Yes, I do a lot of headers during the game, but I never remember any specific header hurting. Today we played in 90+ weather, and I felt dehydrated and started shivering when I was playing. The shivering symptom is normal for me though; I got that a lot when I play in heat. I happened to do a lot of headers today, but I was fine during the game, and don't remember any specific header hurting me.

After the game my headache starts when I drive in the car, but usually after I shower and get somethign to eat it goes away. This time when I got home, I showered, but the pain didn't go away. It actually got worse. I have had a headache for 3 hours now. Right now the pain is in my forehead and above my eyes, but it travels to the back of my skull to.
I don't think it's a concussion, because my eyes pupils are the same size.

Any ideas about what it could be?
Or suggestions on what to do?