Help! Do I go by GA or size on U/S?

According to my first dating scan, I should have been 12 weeks 2 days during my NT scan. Baby had a growth spurt the week before and continued with the larger size measuring 12 wks 6 days. First scan was closest to my LMP and from Ive heard, thats usually most accurate. So when I look at babys nub, do I say its a 12 wk 2 day nub or a 12 wk 6 day nub???

I was wondering the same thing...I think you would go by GA, though

GA

For nub guesses you go by what baby is measuring.

Bump- Thanks for the replies. LoveMy4, why is that? Any other thoughts?

I would go by what they said the baby measured it as x