Dentist appt next week/ severe tooth pain/ on penicillin and tylenol (acetaminophen) 3 for 2 days/ now swelling worse and pain unbearable. should he go back to er?

Yes.: If the pain is getting unbearable and swelling is increasing then you need to be attended to ASAP. Would be better if the tooth were attended to by a dentist so that the source of the infection can be treated and the problem mitigated. Please take action.

Another DDS: If your dentist won't see you sooner, find another dentist. ER won't solve problem.