I'm pretty much the same, gained 13lb in total at the moment. I was 116 pre pregnancy. My midwife isn't concerned, my bump is measuring fine and I have growth scans every 4 weeks and baby is right on track. My last pregnancy I was almost 20lb under my pre pregnancy weight on day of delivery after being very ill with hyperemesis. As long as your dr/ob/midwife isn't concerned, then you don't need to be. I'm not sure how much pre pregnancy weight has to do with it really. I've had tiny friends that have got massive bumps and are very uncomfortable, and slightly bigger friends that haven't gained much/lost weight. x