Twin boys - question

Georgia

Found out at 16 weeks it's twin boys. During the ultrasound the tech said "wow, identical huh?" And I said "wait - not based on what you've told me so far!" She confirmed there were 2 placentas (di/di) but the membrane between the two is now so thin she said if I hadn't asked her to look for the 2nd placenta she would have sworn they were identical twins.

Has this happened to anyone else? I totally get they COULD BE identical - and that only a blood test can confirm post delivery. But why are the membranes suddenly so much closer/thinner? Do I need to worry? Or are my little guys giants and just already crushing into each other?

Just confused and wondering if anyone had experienced the same. Thanks ladies!