So I'm finally having my rainbow baby....

Georgina • Mummy to a yummy 🌈 baby boy 27/07/2016. Preemie 🌈 Twin boys 30/03/2019

So I'm going to finally have my rainbow baby..... or 2!! I went for my early scan expecting to see 1 baby but there are 2 little seeds in there!! What a shock!! 6w 1d. They share the amniotic sack. They both had strong heart beats and nice big yokes!! I'm feeling like the luckiest person alive right now!! But I'm also confused. Does this mean the babies will share a placenta? Does this mean they are identical? Sorry for the questions but this is so new to me?