Repeat 20 Week Ultrasound

I had my 20-week anatomy scan at 20 + 2 and today they called me and told me that they wanted me to schedule an appointment with our hospitals Maternal Fetal Center because they needed to get some more images of our baby girl. Has anyone else had to get an ultrasound redone and if so is everything okay or do I need to be worried? I've read that these ultrasounds to take anywhere from 45 minutes to an hour however my texts seemed to rush through it and I was done in about 15 minutes. She took measurements of a leg bone and arm bone and the head. And check blood flow in a few different places. Should she have done more or took her time? Could something be wrong?