Paranoid from ultrasound

Marie • I am a mother to three amazing boys that are 7,6&5 and am currently 17 weeks with baby number 4.
So when I had my ultrasound for my baby. I am having a girl and she is definitely low and not up top. On my ultrasound they got very concerned about where my placenta is which is pretty much as far down as it can get and they are worried about bleeding which they are positive will happen. Eek. They also could not get a good reading of her spine because it was pretty much down in my cervix. They said it's like a cradle from the way she was positioned. Has anyone else ever had this problem?