Any ideas?

We have a dr appt tomorrow morning but I’m just curious to see what everyone thinks cause Google isn’t helping 🥴

My daughter started with 3 bumps in the morning and I thought they were bug bites but I was changing her diaper tonight they’ve gone up to her butt she still only has 3 on her leg and 3 on her butt it’s not a trail it’s 2 separate things ..

She sleeps in footie pjs with a sleep sack so I’m confused on how it would be bug bites