When will you start to buy things for the baby

Mo • Baby boy 💙 12-23-17 Baby girl 💗 05-26-20

Hello everyone I am very excited to start to shop for my baby once I find out the gender which I'll be 5 going on 6 months ... but everyone keeps telling me it's bad luck and to wait until I am 7 months ... Like I wouldn't buy any big stuff just diapers and wipes etc ... what are your thoughts on this ?