possible concussion?

on friday, my p.e. class was playing soccer. and ofcourse, there's always that person who goes overboard and hits the ball a little too hard. well a boy kicked the ball with full force and the right side of my head just happened to have full contact with it. i was a little dazed and confused when it happened, but i just laughed it off a few seconds later. everything was fine after that and yesterday, but right now i have the biggest headache imaginable. i read that if your pupils are dilated, then u should go see a doctor. whenever i look in the mirror, i think one may be smaller than the other but then again i may be imagining it. HELP?!?!