Anyone experience with flat back symptoms?

[samandriel]

I've had pain in my back, armpit, shoulder, and breast for a while now. I finally got the courage to go to the doctor. I explained my problems, he checked my back but not really my side or breast at all. He said it's because I have a flat back, my posture is wrong and I'm likely to get pain in my back. I said the worst pain was at my side, but he said not to worry because it's normal with a flat back that the pain goes to the side as well. Yet I couldn't find anything online about flat back symptoms including pain in your breast, armpit, side etc. I feel like my doctor didn't examine that part enough (he didn't at all) and I don't feel assured, but I don't want to come back again and sound whiney.
Does anyone have experience with flat back pain which goes to the side and mostly breast and armpit? I hoped my doctor's appointment would calm me down, but it definitely didn't...