Coughing up a lung

I swear it sounds like JJ is coughing up a lung. It started Wednesday night, so I took him to the doctor yesterday. They said his lungs are clear and that it's just allergies. So, I took him to school today and they called to say he was running a fever. And so back to the doctor. They still don't think there's anything wrong with him other than allergies, but they gave him some antibiotics to head off a "slight" throat infection. Sigh. Maybe I need a 2nd opinion - he sounds terrible!