Been feeling mild pain in left temple for three days. no other symptoms (eyesight fine, no pain in other parts of body). do, however, have mild tmj disorder. should i be concerned?

You likely have answered the cause of your left temple pain, as TMJ issues could be reason. Start with a dental consult, as this may be handled with a nocturnal oral appliance. Other causes could be explored if this doesn't solve the issue.

Have you been grinding or clenching your teeth? Have you been fitted for an Occlusal Orthotic, a night guard, to help manage your joint dysfunction? Talk to your Drntist.