why do my ribs and back hurt when lying on my right side?

I have had this back pain for over a month now. If I raise my right hand like Im reaching for something, it pulls on my right side in the rib area. If I lay in bed on my right side, it hurts my ribs and back. Our mattress is a pillowtop so its not a firm mattress. If I am up walking around, and I turn towards the left, it pulls on my right. Any ideas of what could be going on? I know seeing a Dr would probably be the answer, but I don't want to be medicated for the pain. I want to get to the cause of it and going to a primary care would not be the place to start unless I just want to plan on seeing numerous doctors from being referred all the time. Any suggestions are much appreciated.