Small baby

I recently had an ultrasound, because my OB doctor said I was measuring small. Turns out my baby is at 8 %tile on her growth. I'm currently 34 weeks and 5 days. I have two daughters and Their weight at birth was 6lb 3oz and  5lb 13oz. But I was never told that they were low in weight when I was pregnant. Has anyone been told that their baby is measuring at 8 %tile in growth?