You can take him to the Dr to be sure, but if it is roseola I'm pretty sure there's nothing much they can do for it. And if the rash has come out, I'm guessing (?) that he's through the worst of it now. Here's hoping Gracie! Poor little tyke.

Don't stress about it hun, you've done all the right things. But yes, if you're still concerned then take him to the Dr by all means.