Im 37 weeks and 4 days, decided today I was going to get a nice yoga ball. Didn't want to spend a fortune and hate it so got one at 5 and below for $5 and honestly where has it been all my life!!! You don't realize the strain and pressure on your back and hips until you get off of it. Pure amazing feeling to stretch your back out and roll and rotate. I have to say it's a must!