I'm another one who bought a 0-3 "first outfit" that had no chance of fitting, he did wear it briefly while waiting for DH to bring more clothes, but think it got pee on it, as a nappies also didn't fit.
Fortunately we were given a bag of second hand bits including first size from a friend of my mums, only got it a few days before so hadn't even had chance to sort it. DH just bought the whole carrier in to hospital, so just had to rummage through for something that looked like it might fit.
For DD I had a first size outfit, but she still ended up in a hat and cardigan I'd never seen before. She was an ELCS and we were told to bring down hat, vest and onesie, and leave everything else in the room. She was dressed while I was getting sewn up, but apparently our hat was (still) to big, and she was to cold, so they got the hat and cardy from the supply volunteers knit for them (I think using doll size patterns, as she was quite small).
I was a crazy hormonal women, and absolutely loved the cardigan, so I'm ashamed to say I stole it and she also came home in it
(Backstory, if it makes it any better, several family members knitted lovely cloths for my eldest and I was quite put out that no one bothered for my second, I felt like they thought she was less important (^ see crazy hormonal woman), I wanted her to have something homemade too.)