I slept on my tummy most of my life, back surgery made sleep on my right side, and my feet face South-ish. But if I had my "druthers", I'd sleep on my tummy.
My head is generally to the East and feet are generally to the West ... unless legs curled ... hey it happens
I'm somewhere in the middle ... usually on my side, sometimes on my stomach, seldom on my back but have been there
So turned on my sides, I'm actually FACING either North or South ... sideways ... usually
House faces South. LOTS of natural light year round in the front rooms ... I like that
If your feet point west above the equator, they will point east below the equator, but a more important question is how do we really know which way is above or below the equator? It seems like a rather arbitrary concept based on looking at a typical map. How do we know the maps aren't upside down?