Back sleepers

I'm 14w2d and am having a very hard time sleeping in my side.  I have always been a back sleeper and often wake up in the middle of the night on my back.  I have heard that this is very unsafe for the baby.  How true is this?  I will ask my doctor but my next appointment isn't until next week.. I just want to get a comfortable night sleep for once!! Lol.  I hate sleeping on my side,  plus my arms and legs always go numb from sleeping on my sides.  Does anyone have any advice?