It's not bad to sleep on your back. As long as you are comfortable and with good circulation.
My ob told me just make sure to have sa pillow under your back on one side so your not crushing your nerves or your blood vessels. My daughter won't let me sleep on my sides either
I can't sleep on my left side anymore my nerves in that hip and leg get very very painful and I sleep on my back or right side. I am bad!
Yes it is , sleep on you leaft side .it be better .