Downs scare

Lainz
So here I sit 14 weeks into our pregnancy and at our last scan the gynae found that the thickness behind the neck was 2.5mm so when my blood test came back it showed that I was at a higher risk, we went to see a fetal specialist who says he checks for 4 things.
A. The size of baby which was fine
B. The nose bone which baby has and apparently downs babies don't have
C. A problem with the heart which baby has a leaky valve 
D. The thickness of fluid they want it to be less than 3mm and baby's is at the top end of normal.
So now am having a tri screen blood test done which is 99% accurate and am hoping and praying all comes back fine. 
Please does anyone else have similar situation and was you're baby fine??? 
Freaking out somewhat