For the past few days i have felt a pulse in my jaw on the left side. every few minutes, i feel a twitch on my jaw, right above my carotid artery. no pain. is this just a muscle?

Those symptoms may occur when you have a problem with your tooth, gum or oral mucosa, such as a simple cancer sore. You did not state if you have any oral symptom so I guess you don't. At times, a upper viral infection may behave that way although you do not have other symptoms in the oropharyngeal area. Anyway, those are often benign, usually self limited.