HI, What part of Perth are you from ? They should have your results the same day or at least the next day.
I wouldn't worry about the neck thickness as it doesn't matter on it's own. You need the blood test result to know if there is a problem.

The neck thickness for Eleanor was 1.4 which is good but when added to my blood test and age it all came back high risk. I think anything above 3 for the neck thickness they see as a problem but it doesn't mean there is.