My friends let me know exactly how I sleep, since I used to sleep on the floor in school all the time during a free. On my side with my butt pointing out. That's me quoting them, for the record. And apparently it's cute. o_o Whatever~
My guess is that I do the same on a bed too, since I never actually pay attention. I do know that I usually make my pillow a comforter at the same time, so my pillow's at weird angle where it's below my head but also also near my chest.