Harmony Test

Hi mamas,

I live in the uk and had my 12 week scan 2 weeks ago. I received a letter saying I was in the high risk category for DS and to go back to the hospital next week. As I was worrying so much I went privately to get the Harmony test and the results came back as 1/10000 which is reassuring but I’m still so concerned the NHS are going to offer me an amnio. Can I rely on the Harmony test? I’ve also been trying to research why I am high risk, I’m 35, first baby and researching online shows how to asses the NT fold. I think mine looks big on my baby, what do you all think? Should I be concerned or trust in the Harmony test?