Yes I agree with pixie - the screening timeframe is usually 11.5 - 13.5 weeks - and even at 13.5 if bubs measures bigger, they can't do accurate assessment even if dates say 13.5!!

If you have not had previous babies with DS, and given your age - I wouldn't be worried about it too much. Yes, it can still happen but the stats are very small.

At my age I think my risk was 1/180ish - but with bloods came back 1/3587 ish - so just on age alone with 1/2000 that is great. Remember, the u/s is only screening anyway and not diagnostic.

Good luck with your preg.