I had a terrible canker sore about a month and a half ago, located on my top lip. It was pretty big and was white in the middle and then red around it. It healed after around two weeks. The pain went away and so did the white. SInce it has healed, it is still red. So it has been red for about a month or so. What does this mean? Did it leave a scar?

When I say Top of my lip. I mean like inside upper part of my mouth. Right above my front teeth and below my lip