Hello. Thanks for sharing with us your health issues. Hope this answer will help!
First of all there is nothing to worry about a child with
cough, runny nose and
fever which lasts for at least 2-3 days-especially if he is energetic and a good eater. This is because at this age he meets many virus infections and "fights" against them.
Related with
pneumonia, it can be caused by viruses, and usually if he is doing well, if he is energetic and active is left untreated(normal vitals, fever for 2-3 days, normal appetite). If it's bacterial, with fever which lasts more than 3 days, loss of appetite and the child is not active is treated with antibiotics.
If fever lowers after 24-48 h it means that AB has been effective and there is no resistance. The sounds in lungs and the
X Ray changes will last for at least 6 weeks after treating it.
So for being sure that pneumonia is treated I would see the child and his symptoms (no fever, no cough, normal appetite and energetic) and not the X Ray after treatment.
So overall this is the view of a 3.5 yo child in winter!