Yay, so we made it to the magical 12 week point! I am very pleased and grateful that the babies seem healthy. AND that we achieved pregnancy on our first IVF attempt. We know we are fortunate. 
Okay, now onto the fun! I thought I'd share the u/s pic that the sonographer called "the bunkbeds". It was taken at 10w5d:
(temporarily removed - 228 x 139)Twin A is on the bottom, while Twin B is on the top.
So, they look pretty cozy in there, no? I cannot even imagine how much bigger my stomach is going to get!!