Sleep question!

Okay so I am a mom of a 15 month old and I am 35 weeks pregnant. Okay so here's my ?. Unfortunately I made the mistake of letting my son sleep in the bed with us for too long and now there's no turning back until I get him a toddler bed lol, but for my new LO I want him in the cradle next to us for the first couple months and then in a crib. I am also getting a swing for him and was just wondering, if I let him sleep in the swing will it be harder to transition him to a crib because of the motion and him not laying flat??? I just need some tips from moms who have their little ones in a crib! Any advise is welcome!