Hello,
I would see your doctor as soon as possible, it could be bronchitis or a bad case of pleurisy. In any event, you want to have this taken care of before it gets worse.
My sister had this problem years back and thought she was having a heart attack, she went to the doctor and found she had plursey it the next step to having walking pneumonia. You definitely need to go to the doctor asap, before it turns to pneumonia