Best sleeping position for newborn?

So my and my gf are about to have our first baby.​Recently my mom told me to have the baby sleep on it's stomach because if he throws up he wont be able to get it out of his mouth and will choke.​Everything i've read and been told has said to have the baby sleep on it's back but now im worried he will choke to death if he ends up throwing up while we are asleep.​any advice is welcomed. via /r/Parenting http://bit.ly/2FW856e