18 week ultrasound....?

I just got my 18 week ultrasound and after everything was finished, my ultrasound technician had said that everything was okay, except that she saw swelling on my baby's left foot. She said it might be the umbilical cord wrapped around the foot or possibly something genetic. I was just wondering if this had happened to anyone else's child and if not, I was wondering what it might be. I have to wait 2 more days to get another ultrasound done at the hospital to get more in depth, but I'm just sort of scared that something bad might be wrong. Any answers?