If you had serious pulmonary infection previously, then there is a possibility that the fluids have not been absorbed completely, thus partially attaching the two pleural layers. This might have additionally put pressure on some of the nerves in the vicinity which is detected by you only when you take a deep breath.
One other option is that you might be experiencing hiatal hernia. Hiatal hernia is a condition in which the upper part of the stomach protrudes into the thoracic cavity through a weak spot in the diaphragm. The symptoms might be aggravated after eating when the stomach is filled and the protrusion is more likely. X-ray of the stomach might confirm or rule out this condition.