Hi Cheryl, I would not worry too much, the machines and sonographers can be out by quite a bit at times depending on how the baby is laid. I was pregnant with twins and was being scanned fortnightly after 28 weeks and the measurements were up and down all the time, large heads small abdomen (4 weeks too small) but when the babies were born they were perfect size and weight.
good luck and enjoy welcoming your baby.
Me 39, DH 40. TTC 5years
4th times a charm,1-IVF, 3xFET's, 2 chemical
Twin boys born 9/7/08
I agree with beachbaby. That is how my measurements were all the time as well. If the doc says do not worry I would not worry. They will tell you if something is up.
Me: 24 PCOS Husband: 25 Nada!
First IVF Jan 2008 Twin girls!