my jaw has been clicking quite loudly

hi, in the last couple of months my jaw has been clicking quite loudly only on the left side is is rather strange also when i eat there is this kind of pressure when i try to open my mouth my jaw makes this crunching popping sound it is not really that painful at the time it is just unconformable but later on i get kind of head aches in that area, i went to see my doctor when it first started but she didn't know what is could be. do you have any ideas?