To be honest the quidelines change constantly, if there not saying a baby has to sleep a certain way they are saying how you should make milk up etc. To be honest I have always just gone by what the baby wants, and how things work for us as a family unit. I always put them to bed safely, feet at bottom of cot, tuck sheets in, etc but they sleep on their front, when they are on their side they roll over anyway, and when they are on their back they end up sicking in their mouth and to me choking on their sick is dangerous.
I am sure once baby is here they will make up their mind on how they want to do things and they can be very stubborn in making sure they have it their way!
Good luck xx