Rash above sons penis in diaper area

It wasn’t there last night but it’s been there since this morning.

It’s no where else on his body. Just these little bumps right here and a few hidden by his legs. They don’t seem to bother him.

We haven’t used or ingested anything new at all.

My first thought was HFM but he has no other bumps and the first time he had that he had a fever first.

Any ideas? Don’t plan on calling the dr unless it gets worse.