Is it possible to hurt the baby/cut of circulation/pinch umbilical cord when lying in a distorted position?

Unlikely to happen: I wouldn't worry about your positions as baby naturally floats the umbilical cord away from confining positions during pregnancy. Rarely, the babies actions get them into trouble. During the 2nd trimester they have more room to flip & some tie true knots in the cord or wrap it around their neck. It's not usually a problem until labor puts stress on the system, but the monitor will pick it up.