Congrats on your pregnancy, and welcome
My LO is 6w old, and I've coped for since he was born with 20 nappies, but that was mainly because he was tiny and I was using muslins and didn't want to buy more of something with such a short life... Also they dry in seconds.
I'm glad he's now big enough to use other nappies now though (still a bit bulky).
I had 25 flat nappies when I had jacob, used full time, but again they were quick drying flat nappies.
Not sure what you are planning to use, but I think life might be easier with a few more
