Hi, The possible causes are:
Acid reflux : this seems the most likely cause. Such pains can be associated. Chronic cholecystitis : the pain is usually associated with indigestion, flatulence and often with fever and vomiting. A pain from the gall bladder may be aggravated by deep breathing or sneezing as the diaphragm touches the gall bladder.
Pleurisy : An inflammation of the lining of the lungs. This is a likely cause but it is usually associated with some sort of cough and often sputum. Without this, it is less likely.
Costochondritis: If the pain is aggravated by touching, it could be due to costochondritis, an inflammation of the cartilage joint of the ribs.
I hope this answer was helpful. If you need more information, feel free to ask. For accepting this answer, please click on the green 'accept' button below. Feedback/Bonus will be warmly appreciated.