After having my bump in the way for ages and never being able to lay on my front and get comfortable, I've finally found a solution.
Just make a mini fort type thing, one pillow for under your pelvis and either three pillows for the side and front, or a bolster pillow in an upside down U shape for the sides and front. There's a hole in the middle. Bump goes in the hole, you get to lay comfortably on your front with no pressure on your bump 