30 Weeks

I had my 30 week check up on Friday. I should find out early this week about my glucose tolerance test. No signs of preterm labor. The only thing she did say was that I was measuring small for being 30 weeks. She ordered an ultrasound for Thursday to get more accurate measurements. It didn't occur to me to be worried about it until I came home and Charles asked if we should be concerned. So, of course, I started googling and web MD-ing...and needless to say, I'm worried.

Have I been eating right?
Is my placenta doing it's job?
Did I eat something dangerous?
Intrauterine growth restriction?
Low amniotic fluid?

And that's not even the tip of the iceberg.
Four more days until the ultrasound...