I feel it in my back, but only when I walk or stand for long periods of time. My back was hurting more before, then I adjusted my chair some and that has stopped it to where I only feel it now when I walk or stand a lot. I guess my growing baby bump changed my posture needs while sitting and adjusting my chair fixed it some. My tiredness has come back some but still not as bad as first trimester. I'm back to taking naps though.