Baby Gear Question?

I live in a one bedroom apt and will be sharing a room with the baby. I planned on her sleeping in the rock n play sleeper but was also going to get a pack n play just to have on hand for when she hits that certain month when she'll transition into that and also to use the diaper changing thing they all seem to have. I'm due early March and was wondering if its necessary to have the pack n play before she arrives. Should I just wait till she gets a bit older and buy it when she's ready to transition to sleeping in the pack n play or should I get it now? I just don't want to be crowded with a bunch of stuff that isn't really necessary right away but I also feel weird not having a "crib" type thing for her.