Stinging And Pulsating Feeling In The Chest And Lower Ribs. Pain Increasing. Cause?

I have an odd feeling in my upper chest area and the right lower ribs, it's kind of a stinging pulsating pain that lasts any where from seconds to several minutes. Some times it radiates to the back of my ribs and shoulder. It's usually not there, but lately it's been waking me up at night, or suddenly happening while I'm doing my daily activities. And, no, I'm not over exerting, just normal daily routine.
I sometimes take an aspirin to help it, that works once in a while. Other times I take an antacid, which works once in a while... nothing seems to help consistently and the pain is increasing sometimes to the point of tears.