what i try to do when sleeping on my stomach is have one leg pulled up a little and slightly bent, so there is not quite as much pressure on the baby, that might help! but also when it gets uncomfortable try a side sleeping position for me it helps if i have a pillow between my knee's. Good luck
Thanks alot cause I was worried that I am blocking oxygen from my baby.
I agree with queenspade! You'll know when you need to stop because it'll be uncomfortable~
I really don't think it matters. This is my 5th pregnancy & I have slept on my stomach with all of them for as long as I could. When it gets too uncomfortable you will know. I do know that later in preg. they recommend sleeping on your left side for better blood flow & oxygen etc.