Well, I had my scan at 8 weeks and one was active, one was not. I did not get another scan until 18 weeks despite the fact that I told the Dr I felt like something was wrong. I never felt Baby B move but felt Baby A all the time. He chalked it up to the way my uterus was shifted and refused me an ultrasound. At the 18 week scan they found Baby B "shrink wrapped" with only 2 cm of fluid in the largest pocket and Baby A with 12 cm of fluid. Of course, I have since then switched Dr's, we had surgery and now it is full remission. My boys are healthy and their fluid levels are completely equal so don't let my story scare you one bit! Make sure you ask the sonographer to show you the babies bladders with each ultrasound. That is a good sign that each baby is getting enough nutrients to produce enough fluid. Even though the fluid levels for my kiddos was drastic, they each had good bladders. I attribute this to the fact that we caught and treated out condition early enough.
You are doing great mama. I hope my experience can ease the minds of the women out there carrying identicals. I know when I got the diagnosis, I had very little hope. What I found on the internet was grim and led me to believe that my boys did not have a fighting chance. But I have been educated by some of the worlds best Dr's that medical advances have changed so much in just the last 1-2 years. Most of the info you find on the internet was during a time when the surgery was not an available option for people. The surgery I had done in Oct has only been perfected in the last year or so. If you ever have questions, I am always so happy to talk about it. I know the fear you are feeling right now. I have spent most of my pregnancy worried about the health of my babies and I am glad that I can say I have done it and overcome it.