Over 24 hours later, and the thing hasn’t changed in appearance, gotten bigger, etc. It also hasn’t disappeared. Based on what I know about cold sores, it doesn’t seem like one to me. I think just because it’s on the edge of my lip that it has my attention. It doesn’t seem like a pimple either. Maybe an ingrown hair? I guess there’s nothing to do except wait. Man, I wish this thing would be gone by morning so I can stop worrying.