What could this be?

Kim • 👼🏻MC 12/5/17👼🏻💖09/2018💖💙11/2019💙💖02/2021💖💙01/2022💙

Does anyone know what this could be? A few weeks after she was born she had some baby acne so her doctor gave me some cream to put on her and it went away but now she’s almost 4 months and this has been there for a week or two. It’s only on this side of her cheek. I’m definitely calling her pediatrician tomorrow.