Have any of you had to re-do your ultrasounds because baby wouldn't cooperate? I had my 20 week ultrasound 2 days ago, and the technician wasn't able to get all the measurements she needed. I went in for my regular OB appointment today, and he said I will have to do another ultrasound in a month. He said everything the technician reported so far was ok, but I still can't help but worry.