38 weeks pregnant

Last Tuesday I went to my 38 week appointment, and they did an ultrasound to make sure the baby is growing well enough with my thyroid problem. They estimated that the baby weighs 8 pounds and 2 ounces which is in the 80th percentile for 38 weeks!! They said they can be up to a pound off, so hopefully they estimated a pound too high instead of low! And along with learning that I have a BIG baby, my cervix has not dilated or effaced at all! Now I'm afraid that if I go over my due date, I'll have an enormous baby. I have my 39 weeks appointment tomorrow and hope that something has happened within the last week because it's so hard to be patient right now. But for now I'll just enjoy the little bit of stress free life that I have left.