Umbilical infection?


I can't get a great photo of it, but I noticed yesterday there was a little red spot on the skin of my week old baby's belly button, right above the umbilical stump. It looks slightly raised, and red. It's definitely his skin, not part of the cord.

He doesn't seem sensitive in that area. It might be a bit darker of a red today. It looks a bit like a blister maybe?

I'm worried that it's an infection, but it doesn't look as awful as what google images suggests an umbilical cord infection looks like. Articles I've read on what's normal and what's not leave me feeling uncertain.

We have a scheduled pediatric appointment the day after tomorrow. Should I worry? Should I wait for the appointment? Should I try to move the appointment forward? Anyone have any experience with this?

Thank you!!!

The picture below was from yesterday, but also different lighting. It's only a bit worse today, but the new pics make it look much worse.

ETA: the dark red/orange part, the blister, is his skin for sure. Touching it, it's very soft and loose. It moves easily. Like a pustule maybe more than a blister.

ETA 2: some orange-ish pus came out of the blister/pustule