If your only a month, I'd definitely wait. As exciting as it is to find out your pregnant there are soo many things that could go wrong. The first time I found out I was pregnant I started buying things right away, and a month later I miscarried. I know its hard to think about the fact that the baby could die right after finding out but you need to keep the possibility open that way you don't waste a bunch of money. Most people wait until tweleve weeks to even tell family and friends just because they don't want to cause heartbreak if something were to go wrong. I'm currently 18 weeks pregnant and still haven't told anyone or started buying anything, Im waiting until I find out the gender in two weeks because then I'll be more convinced I'll actually go full term. I've just had so many heartbreaks. I hope that helps. Good luck.
I forgot to add instead of buying everything just save the money you would be using so you can get what you need even when money is tight.
We didn't start getting things until after we found out the gender and at that time my husband was unemployed, but really we didn't buy anything because we had a gender reveal party which had a diaper raffle and family brought lots of diapers. We've only spent money on her nursery stuff and clothes from resale shops because as long as their clean, not stained or torn then there is no reason not to use them since they're cheaper. Your baby won't care lol. I'm 7 months now and we still have the shower in April soooo not really worried about anything. Plus we went the cheap route. We saved from each paycheck as well. But it also depends where you live, prices obviously vary from location. If anything, best advice is to buy online.