Couldn't get Nuchal Measurement...

Vicki
Hi Ladies...
We had our scan yesterday :) All looked well and baby was wriggling around like a mad thing.
The only problem was we couldn't get the Nuchal test done because the neck wasn't visible. I have to wait for a quadruple blood test at 16 weeks which I've read has an increased risk of giving a false positive meaning more stress and a decision as to whether to have CVS.
Anyone else have any thoughts?? 
Hope everyone is ok today X