The last time I was at the dentist, I had a similar experience. SHe was preping my tooth for my first crown ever. The novicane wore off when we were almost done and was HIGHLY sensitive to the cold pressured air they put in there, so she gave me another shot! Well, I have NEVER had this happen, but my cheek was SOOOOOO sore, it hurt more than the tooth! I felt it almost immediatly as she applied the second shot and it stayed with me for a few hours and thank god it went away. I was miserable! I dont know if she pinched it or what, but I thought I would die! Good luck to you. Hopefully it is all healed by now, but I watned to just share my story with you as well, and let others know too, that it can happen to you!