|I had 13 newborn Sandys and 24 OS diapers. I wanted to use CDs right away because I heard of many parents who get into a routine with disposables and never make the switch. My newborn Sandys lasted only 2 months though, and I slightly regretted buying them.
Right from the start we used the OS with our son, who was born at 7 pounds. I thought it looked ridiculously bulky at first (I had never seen CDs used on anyone) and I thought there is no way it could contain anything, but we never had a leak! Only thing is, we needed bigger outfits with the OS so the newborn diapers were handy for the cute newborn outfits. But you can certainly skip them if money is tight... I would certainly try the OS right away, and test them: you may think they look too big on your newborn, but they may still work just fine. Besides, everything always looks too big on a newborn!
Congratulations on you LO and good luck... Just 2 more months!