I've noticed that I have awful back pain depending on what I wear. I was wearing jeans the other day, and my back was killing me, all the sudden the elastic broke and a few minutes later my back felt tons better. I didn't think that they were too tight, but apparently they were! But other than that my back pain hasn't started yet, I don't usually have really bad back pain, until the last few weeks of pregnancy. I hope yours starts to feel better soon.