Wait or Go?

My 3, almost 4, month old has had a little red area for a couple weeks. It started out just red, then got looking like a little rash. I put diaper cream on it and this eczema cream on it because it seemed like diaper rash or eczema, but now it looks like this and I'm not so sure. We have an appointment on the 7th, should I go or wait? He doesn't seem bothered by it at all. Anyone know what it could be?