Sorry it has taken so long to get back, but the other girls have given you good info.

The NT measurement by itself is not usually used to determine risk, because by itself it has a high false positive rate (compared to the combo of NT scan + bloods)

In saying that, below 2.5mm (or even 3mm towards 13 weeks gestation) does not usually increase the risk figure. So, your measurements were fine.

I think the sonographer was wrong in giving you some info without explaining properly, or you having someone to get the info from. Especially as you are also waiting on bloods.

When was your blood taken? Results can sometimes take more than a week to get back. It is better if you have a proactive dr who will follow up with the lab.

Please try not to worry, an accurate risk figure is based on age, blood plus NT measurement. And it is only a risk figure, even if the combo comes back with a higher risk, this is not definitive.