I Have Been Experiencing A Throbbing Pain In My Right

I have been experiencing a throbbing pain in my right neck just below the jaw line - in the same place you check your pulse for a couple of months. It either aches or throbs - all the time. my doctor checked for a blood clot and found nothing - so left it alone. Any suggestions of other reasons for this pain. Not sharp pain, throbbing and dull, but constant.