pcs??

Hello my name is travis. Back in 2006 i received a bunch of blows to the head during a boxing class. That whoe night and into the next day i had a really bad headache that was literally pounding inside my skull. I should have went to the doctor but  I didnt. Since then ive been dealing with head pains on and off and this weird feeling inside my head that i cant describe. It almost feels like a constant uncomfortable pressure inside my head or something. I went to the neurologist now in 2012 and he said i may have Post concussion syndrome. Im waiting to go for an emg test to rule out a pinched nerve and im also going to get an EEG test to see how my brain in functioning. The weird thing to me about saying it "PCS" is the fact that for all of 2009 2010 and 2011 i was perfectly fine. I didnt have these pains on a day to day basis at all and never had that pressure or uncomfortable feeling in my head. Is it possible for me to be fine for 3 years and then my symptoms from something that happened in 2006 come back out of nowhere? Or do you think its something else causing my problem?