Twins? Huh?
My RE took measurements and said the sac was measuring right on track at 6w4d and then she zoomed in and we saw "a" flicker. A few minutes later she tells us we are amongst the 1% who have an egg split and showed us two flickers--identical twins.
We have a long and uncertain road ahead of us, so we are not sharing that part of the news with our families quite yet--but ohmygoshtodaywearepregnantwithtwins!