Fluid on cerebellum, baby measuring small, etc

Y’all, I’m so worried. Yesterday’s appointment with the high risk doctor didn’t go well. Baby A is measuring 7 oz and Baby B is measuring 10 oz. With a 30% difference, she’s concerned. She said they don’t like them to be over 20% different in size. Baby A also has fluid on the cerebellum, and the cerebellar vermis (that separates the two sides of the cerebellum) is thin. I don’t really know much more right now except I will have to go to the high risk doctor for the rest of my pregnancy. I go back October 30th for another sonogram, and if she’s still seeing these issues I will be scheduled for a MRI. She did do the blood test yesterday for Down Syndrome and Trisomy something (two different ones, but I can’t remember the numbers). I hate waiting so long to know anything. I will get the results from the blood test in 7-10 days. They could’ve done the amniocentesis, but I declined due to the high risk of loss from it (1 in 50 babies). Has anybody experienced anything similar?