breastfed baby / red bum

As

my lo was born the 16th of july & has pretty much always had a red circle around her actual bum hole . it’s not tender or sore when changing her diaper & doesn’t bother her at all . i’m worried because i’ve used 2 different diaper rash creams & it’s just not clearing up . what could this be ? i can’t call her pedi until the morning .