Knowledge about recurrent infections is no substitute to clinical examination..as children deteriorate faster ...
Investigations or no investigations should be prerogative of a Doctor ..
In most situations unnecessary tests confuse disease plan ..eg often children with viral infections have high counts ..
But if a child has fever but without classical viral symptoms , one must rule out urinary tract infection as it has potential for recurrence...
Antibiotic if started under some doubt , it's better to complete the course as suggested by doctor..
Do trust your doctor otherwise simple problem turn in to complex one...