J.S.
You know, I've always wondered that myself, LOL!! But, I will admit, that with my 2 younger kids (3 & 7mo), I would always place a larger pillow under my butt to kind of elevate myself! I really couldn't tell you if it makes a difference or not. My husband laughed at me every single time!! I got pregnant right away with my 3yr old...Like literally the same month I got off the pill. With my 7mo old it took about 4mos. But, like I said, I always put a pillow underneath myself for a little while!
Don't think too hard about it...That ends up taking the fun away!
Good luck with #2!