What could this pain be?

Ive been getting a pain in the back, left side of my head for a day or so now. Its a twinging, sharp pain that comes every few minutes or so. Its not painful enough to make me cry but is very uncomftable. I also have mouth ulcers in my mouth on the same side. I was wondering if anyone had any idea what cauld caue this and if the two maybe connected? Im going to docs tomorrow but would be interested to hear if anyone knows what it could be