Re: How late in your pregnancy did you find out you were having twins?
It's unlikely to miss a baby on u/s at 7wks, but it can happen.
I found out about my first set at 5.5 wks. Second set at 7.5 wks. Third set at 7wks.
I lost one of the 3rd set.
Congrats on your pregnancy!
Heather SAHM to 6 who are 7 and under, including 2 sets of twins and our last little miracle, a surviving identical twin, born Oct 2012!