Pregnancy sleep positions

Allie
Hey ladies! 
I've been reading a lot of posts stating that sleeping on your back/right side is bad for the baby and can cut off blood flow. Up until this point (I'm 17wks today) I have been sleeping either on my back or my right side. How worried should I be?? It hurts to try and sleep on my left but I guess I'll need to start doing so. Any advice/reassurance is much appreciated. 
Thanks! 💙💙