I thought I was going to CD as soon as I brought my daughter home from the hospital so I even refused a free pack of disposables that they offered, but I didn't start CDing until week 5. I was just nervous starting CDing so that was a big factor, but the other thing was that the infant prefolds I had were too big for a newborn. Even 7th gen or Whole Foods brand diapers were too big even though I had the smallest size and the only thing that fit were pampers swaddlers. If I had to do it all over again, I'll probably take as many free disposable as possible from the hospital for the first week or two. You probably want to use sposies for the first week anyway since the baby has meconium and it's too messy to deal w/ on cloth. That stuff is like tar! When I have another baby, I'll probably try to start CDing at week 2 at the earliest and maybe get some smaller diapers than infant prefolds in preparation.
I also refused the petrolatum that they had at the hospital to put on the baby's bum so that meconium comes off easy because I bought a natural butt balm. Next time I'm going to take as many freebies that the hospital offered and that's my advice to you as well! Take the aspirator (even though it says disposable...it works better than the ones at the store) and anything else!