What type of twins are they?

​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​The US tech didn't give us any details other than "yep! Its twins!". Is it safe to assume they're definitely NOT di/di? But from there, any inkling to the type of twins they could be? (This is a 7 week US: baby a measured 6w5d and baby b measured 6w3d)

Bottom pic is the 2 yolk sacs if that makes a difference?

I don't see any dividing membranes separating them. But could that just not show yet? Thanks!