I have had this several times. I am actually dealing with something similar right now, a sore pain that runs up along my carotid, along my jawline, and inside my ear. It is intermittent, mostly a soreness and sometimes I get sharp jabs of pain. The good thing is that I have had similar situations before and nothing has ever been wrong (proven by ultrasounds, MRI, MRA...). I don't know exactly why it happens, but it always gives me a scare. Thinking it's probably muscle or ligament related.