Multiples

twins, one sac

Hello! 
I went in for an early U/S at 4w5d because I have had a mc and wanted to be extra careful. I saw one small black spot, which the doctor said is fine. He said he can't confirm or deny twins. However, my other doctor is monitoring my HcG and (during the scan) called me to tell me it's definitely multiples. Can someone please explain to me how one small black spot on the screen could hold more than one baby? Does that mean they're definitely identical? Or could there be babies from two separate fertilized eggs in there?
What is the difference between a gestational sac, an amniotic sac, and a yolk sac?
Thank you!

Re: twins, one sac

Sign In or Register to comment.
Choose Another Board
Search Boards
"
"