Does this look like a 5th disease spot?

Took my 2 year old to the doctor yesterday for cold/flu symptoms and they did an exam and said it’ll just run its course. But today he has this red spot that showed up maybe 20 hours ago. Does this look like 5th disease? Doctor said to call back if he has a high fever or is inconsolable, but he’s acting normal and no fever. I have a newborn at home so I’m extra worried.