Fevers & headache

So my 6 year old son has had a headache all day where he doesn’t want to do anything but sleep, he has had a slight fever that’s gone up to 100.1 so far. A very very slight mild cough. Medicine isn’t breaking the headache or fever. Should I take him in to get covid testing? He has a very terrible immune system and is always always sick, he also has autism (if that makes a difference) I also have a 6 mo baby that he’s very attached to so I worry about both of them getting it. We are currently staying at my moms house in the basement rooms while dad has baby at home, so we’re staying isolated.