Well I'm 15 and I had a volleyball tournament yesterday'. I was at the net and a girl from my team missed her serve and the ball hit me in the back of the head, hard! Immedietly after everything got blurry and I got very dizzy. I had very bad ringing in my ears and one of my teammates said my pupils got really big. Later that night I got a terrible headache and have had it all day today I feel very sick to my stomach also. The ball hit the bottom of my head/top of my neck. Do I have a concussion?