I got told that as well. My perinatologists Dr said that within the first 24 hours of conception after the egg splits into 2 they can form their own Sacs. Giving you identical di/di twins. ?

Isn't it weird that "medical professionals" can be so uneducated about their own field?! It's mind boggling!!

The first nurse that came in to see me told me that my two girls were fraternal but right after the main ultrasound tech came in and told me that there is a chance they could be identical

I am also expecting same sex di-di twins and my ultrasound tech said there was a 30 % chance they could be identical. A lot of people deny that possibility though.

Yes, that is correct. Placentas and sacs aren't the end of the story, genetics are. I'm having same sex di/di. Identicals having same placentas, sacs, or different, is dependent on when the egg split. We probably won't have ours tested unless a medical reason comes up.

@mrsnobby I tested mine as I wanted to know for sure and they are identical (even though I can't see it!) x

There are a few ladies on bb that have had di di twins and had them tested and they were identical.

I've never been told whether they can be identical or not as my di/di twins were the result of a two embryo transfer so my ob said they were most likely fraternal. Turns our they are boy/girl so 99.9% sure they are not identical. But I've done research on it and if the egg splits early enough, the twins will appear di/di and still be identical. The research I've done said about a 30% chance, like you have found.