Minor concussion....?

Yesterday, I was playing capture the flag with a football with some people. A high school football player ran at me at full speed and knocked me down (by mistake). I fell on the turf on the same side he hit me. I got up right away because it didnt really hurt but later that day I kept losing my balance and then this morning when I woke up, the side I fell on hurt so much and It hurt everytime I laughed or even breathed hard. But just about 3 hours ago I started becoming dizzy and I couldnt even stand for about 30 seconds without getting dizzy and my hands keep shaking. It is starting to get alittle better but my head feels so full and Im still a little dizzy only when I stand. Do you think I have a minor concussion? Thanks for your help.