Im 27 weeks, try getting a body pillow. Thats the only thing working for me. If i forget to use it, im on my stomach.
I'm 17 weeks and I find sleeping on my left or right side uncomfortable. Even when I start off on my left side somehow I always end up on my stomach. So no CorduroMommy you are not alone. Im trying hard to break the habit. Thinking about buying a body pillow to prop me up on my side and prevent me from laying on my stomach.
I'm 10 weeks and since about a month now I've been forcing myself to sleep on my left side as much as possible. I hear this position is better for blood flow. if unable, I sleep on my back or my right side, but I avoid sleeping on my tummy as I dont wanna inhibit my belly growth.
I dunno if this makes sense, and it probably doesn't answer your question, but I just thought I'll share.
good luck to you :-)