My headaches are in the same spot every time, usually in my temple and the area right above my left ear. Its uncommon for tension headaches to be unilateral, but in my case the things that contribute to the headaches just make it that way!
Anyways - If I were you I would visit a dentist and have them check out your bite alignment - thats what my problem was. It couldn't hurt, and it sure beats taking medicine for something you don't have!
"You cannot hope to build a better world without improving the individuals. To that end, each of us must work for our own improvement and, at the same time, share a general responsibility for all humanity, our particular duty being to aid those to whom we think we can be most useful." - Marie Curie
"The pessimist sees difficulty in every opportunity. The optimist sees the opportunity in every difficulty." - Winston Churchill