You can start packing your bag whenever you feel the need to. However, according to the NHS, you should have it ready to go by 37 weeks. Some women like to start putting in basic items like babygrows, hats and mittens from around 20 weeks, especially if they’ve found out the sex of the baby.
If you start packing your hospital bag with the basics from 30 weeks or so, then even if you go into labour early, you’ll have most of the things you need for the birth.