About three days ago I noticed a small redish sore
inside of my lip
. On the second day, it developed a translucent bubble, but went away the same day. Now it's virtually not visible. I only know it's there because I can feel it with my tongue. It hasn't grown in size, changed in color, or been painful at all. I also have a sore throat and runny nose, but no fever.
Is it a cold sore, or herpes, or something I should be seriously concerned with?