1st time around we put our pram on lay-by at aroumd 25 weeks and got it out at around 35 weeks. My mum bought our car seat at around 30 weeks. We got it installed about 2 weeks before my due date. This time we'll be buying the pram after bub is born and bub will be having Lily's car seat, so we are buying a convertable booster seat probably a couple of weeks before bub is due.