Tell me your outcome

I am 7 weeks and a few days pregnant. I found out I am having twins. Each in their own sac.  They found baby a's heart beat right away and it was super strong.  By when they went to look at baby b they couldn't find a heart beat or a fetal pole. The nurse explained to me that it is likely that baby b may not be a viable pregnancy and will kind of just disappear but I will have another ultrasound next week to see if anything developed.  Has this happened to anyone else? What was your outcome?