Pain On Right Side

I have pain on my right side just below my ribs. Sometimes it's a sharp pain, sometimes its a dull pain. Then there is times it feels like a muscle cramp, but deeper than the muscle. Kind of like a ballon swelling up below my ribs. It will last for 10-15 seconds, and will do that off and on for like a minute. After it's over, that area is extremly tender. Any ideas that anyone has I would appreciate it greatly.