Most important, don't allow your kid to meet grandma or grand parents....he is potential career..I know adult physician will say, child don't have much symptoms so don't check for 3 days but understand whether you go for covid test or not...keep in mind your child will be infective to other for 10days from onset of symptom...
For your kid symptomatic treatment is all that require
Next Steps
Covid antibodies test...as children are nit that much cooperative for nasal sample for rtpcr