anyone had experience with umbilical cord or fear

I'm very greatful for my pregnancy and I just feel bad seeing the ppl who had lost experiences from umbilical cords. when I went to the doctor for my last ultrasound in July she said I couldn't see the 3D that well because of the umbilical cords it just kind of gives me a little fear that they may interfere God forbid I've seen stories and it just made me a little paranoid please give me your experience opinions and most motivating feedback