Thanks, everybody! I'm sorry if I'm taking up your time on this board with something that may turn out to be nothing, but I've definitely been losing sleep over this. Thanks again.

PS: I never noticed any pus/bad taste in my mouth.

PPS: Abcess did cross my mind. If it was an abcess, I would think that the dentist would have seen it and known what to do, without referring me to a specialist.