Does this mean I have a concussion?

I was playing basketball today and I was elbowed in my nose while I was going up for a rebound. My nose bled and I got a headache. Does the headache mean I got a concussion? I may be wrong, but the following page seems to say that a headache means it's a concussion: http://www.mayoclinic.com/health/concussion/DS00320/DSECTION=tests%2Dand%2Ddiagnosis