I had mine ready and in the trunk at 35 weeks you never know and it's better to have it done and out of the way than be running around trying to throw it together if your water breaks at 36 weeks.
I wouldn't worry too much ! lol if you look at stats it's actually not that common to go early especially for 1st time mums.. NOT saying it wont happend lol ! I packed mine at 37 weeks and keep rechecking it lol the longer I have been waiting the more bits I keep adding lol ! I now have 1 large hospital bag and a smaller one lol
I'm packing mine after my baby shower in april..this is my 1st but I've already been told that I have to rest a lot right now or I could end up having him early
I had mine packed at around 30 weeks with both. My second pregnancy I wanna say closer to 25 weeks because I had pre term labor starting at 20 weeks. I also went into labor at 37 weeks with my first, and same with my second. So I'm sure ill pack around 30 weeks again!