Does anyone know what this rash is??

My daughter is 6 months and had little red bumps on her tummy that I thought was maybe a little heat rash, well that was a week ago and it hasn’t gone away and today I look at her part way through the day and she’s got little red spots all over her tummy and back, but not anywhere else . Is this a heat rash? Or an allergy? Something else maybe? I’m gunna make her a dr appointment Monday but her dr isn’t open on weekends so I’m not sure what to do. She’s acting totally normal so I don’t think they are bugging her.