I have two herniated discs in my lower back; I had the same fear that it would hurt during pregnancy, especially the weight pulling me forward. However, to my surprise & delight, my back didn't hurt at all when I was pregnant (at 30). Actually my chiropractor told me that when you are pregnant there is a chemical called "relaxen" that kicks in and can alleviate or make those kinds of pains go away (for the pregnancy). I didn't have back labor as I feared I would either, but that has more to do with the position of the baby. I also have a long torso, so that might have had something to do with it - more room for the little guy!