I do have a history of low back pain, but this is completely different. Just anterior to my lower ribs on the right I've suddenly started to experience pain. I was sitting at a computer chair and raised my arms to stretch and almost felt a strange 'pop' and the pain started. It doesn't hurt when I am in a stationary position, only when moving. I've noticed that my shoulder is even dropping on that side in a guarding pattern. It is a little sore with inspecting contact but not like the usual pain itself. In bed I've also noticed it feels better to lay on that side, laying on the opposite side causes it to hurt worse. I was thinking a kidney problem at first but it's higher than that and I've not been experiencing any urinary problems that are associated with kidney issues.