who else?

I went for my routine appointment today (28 weeks 2 days) and am measuring a week behind and will have to have an ultrasound done to see where I'm at. When I had my first dating appointment the baby measured 4 days smaller than my ovulation date and the doctor said to not worry as it wasn't more than 5... but  I'm wondering how many of you ladies are in the same boat? Did you freak out a bit when told this? Was everything ok once the ultrasound was done?