4 weeks ahead of schedule??

when I went in for my 30 wk appointment, I was 29 weeks and 5 days. my fundal height/stomach measurement was measuring at 34 weeks. I asked her if it could be because I'm plus size and was bigger when I became pregnant, and she said no. they set up an appt for the 20th of November for an ultrasound to get more accurate reading of baby's weight and height. has anyone else had this happen? was your baby healthy and okay? did you go into labor early? did they induce you? did you carry full term, but have to have a c-section? I'm so full of questions and won't get any answered until the 20th. please help.