When is it 'ok' to buy baby stuff?

Lorena • Momma to 3 beautiful babies!🤍🤍🤍
I'm 21 weeks and have bought my baby boy a few outfits. Today my husband and I went to look at strollers and car seats as well. We went to my brothers for a get together and mentioned it to them that we went to see that and will be getting one next week. He made a comment about how we shouldn't be buying clothes or anything till I'm already with my baby in hands because 'you never know' it's our first baby and we are so excited. Obviously things can happen but we just want to enjoy it the most that we can. So when did you ladies start buying stuff for baby? When is it considered 'ok'?