Diaper sizes ?!

Ashli
Ok I've been racking up on diapers before my baby's arrival I just have one question. I was a 7pound baby & he (boyfriend) was a 10pound baby so I'm just going to assume I'm going up have a big one ! Lmao. I've been getting size 1's. It's says on the box 8-14 pounds, is that ok for a new born or do I need to get a size N from now on ? Which just says <10 pounds.