I think everything will be fine.
I had "contaminated" urine during one of my tests and they requested another. That freaked me out thinking what could be wrong. But in the end it was fine. The sample they had was just not a very good one. Same with your ultrasound. Perhaps that was them saying the person doing the Ultrasound was crap.. and didnt know what they were doing? Or maybe it was just bub's napping time. Ive had friends who were told to go for a walk and come back in half an hour, because they couldnt get any measurements.
Youll be right.. just think, you get to see bubs again!