MyAngels......

I dont have any experience with this but, babies at this stage are soooo small.... if the sonographer was even one mm out, and you have a small baby, this could be right, and baby is fine!
I know its hard not to worry and over analyse...... I know I probably would!
The table on page 4 of this http://www.bmus.org/policies-guides/...61_ultBMUS.pdf shows what the dr's use..... If your dr didnt seemed concerned, I dont think you should be too worried (again easier said than done ) That heart rate is good for that age!

Good luck hun have a H&H pregnancy!