So I'm 27 weeks prego and all the ladies I see during the day tell me my belly is small for how far along I am. Doctor says everything is fine so I'm not worried. But because my belly is "so small" I had been disregarding all the advice to keep off your right side or back when sleeping. (For anyone who doesn't know, it is supposed to keep your blood flow strong so it gets to your brain alright) so tonight I'm surfing the web and laying on my back and I start feeling very strange. My head starts to feel funny and it's slightly harder to breath. Once I rolled to my left side my vision started to get clearer (something I didn't even realize was being affected at the time) and my breaths became easier and my heads became clearer. Did not expect that! So I guess it's my left side from here on out ladies! 
Im sure it's different for different women. Just wanted to post this in case anyone is in my shoes where they didn't believe it would make a difference sleeping on one side over the other!                
                             
        
Re: Cautionary tale
Basically just listen to your body. I slept on my stomach and back until my body told me it was time to change positions. There are some people who can continue to lay anyway they want to up until they give birth. Others have to accommodate their bellies earlier in pregnancy. Don't scare people into sleeping a certain way if their way is still working for them.