Does this sound like a tooth infection?

about a year and a half ago (give or take a few months) I had a root canal done on my right middle tooth under my nose. I had it done because about 2.5-3 years ago I had a broken tooth and they capped it and after a year or so it got infected. I remember that when it was infected I had a pain at the corner of my nose. I also had redness above the tooth and when I pressed down on it it hurt also. The last few days I have had a pain at the corner of my nose but my gum isn't red and when I press on the gum it doesn't hurt and feels "sturdy" I guess. It doesn't hurt either when I chew or bite down on something which I also remember from last time. I think it may just be a pain in the a$$ zit that isn't showing it's ugly head yet but that's what I thought last time too. Is there an easier way to tell if it is a tooth infection? If it is wouldn't the gum be red by now or at least sore to the touch? It's been about 3 maybe 4 days since it started.