Mum bought DD a pair of socks with embroidered bees on them quite early, about 6-10 weeks I think.
I wouldn't let DH buy anything until after 20 weeks. Don't know why. So we bought a pram, then a cot/change table. And then the rest after that. It was about new year sales time anyway. However after the poor buggar dragged it all up stairs, he wasn't allowed to touch any of it until after 30 weeks.