I was told to fast for 12 hours. I personally don't think 8 is enough. Especially when you're preganant.
When you're pregnant - your digestion slows down considerably and I'm suprised that they would take your blood only after 8 hours.
I would ask them about the 12 hour thing....and honestly, even if they say 8 is fine, I would extend that to 12 -
Best of luck and God Bless,
IT'S A BOY!