Advice needed! Nervous but trying to remain calm

I'm 34 weeks along today and I had to have an ultrasound today because my fundal height was measuring the same as last week's, putting it a week behind. During the ultrasound she was measuring and said that my baby's abdomen was measuring 1 week behind. That's the only info I got besides the fact that shes head down, her heart rate is 140 and she weighs 5lbs 7oz. The ultrasound tech sounded very optimistic, saying everything was looking good but that 1 week behind thing made me a bit nervous. Anyone else have this happen and can you tell me what I might have to expect? Other than that, I got a cute new pic of my daughter <3

Also, in another shot, that they missed, she has so much hair! Already!