Pneumonia is an inflammatory illness of the lung. The alveoli in the lung typically fill with fluid. This can be caused be a variety of things including bacteria or a virus. A chest x-ray is usually used to diagnose pneumonia. Signs can include cough, chest pain, and fever.

Bronchitis is also an inflammatory illness but it is specifically inflammation of the large bronchi in the lung. It too can be caused by bacteria or a virus. A common sign is an expectorating cough (phlegm).

They are similar so I can totally understand your question. Not sure if this info helps you out at all. The chest pain and fever say pneumonia to me. Hope you feel better soon!