My NT measurements at my ultrasound came back good, but my bloods suggested the pregnancy was HIGH risk. My DS was initially an identical twin until a dating scan at around 10weeks showed i'd had a likely missed m/c. That was the only reason for my HIGH risk blood results, and my carers urged me to not worry.
Not the same as you as your journey as such, but some similiarities.
I hope your journey is safe with a happy ending. xx