hospital bag....when do you pack it

November til January 5 for a short cervix. Was able to go back to work part time since my cervical measurements were staying stable. I am now 32 weeks and want to prepare for baby girls arrival but am unsure of when is a good time to pack hospital bag and have the car seat put in. I'm worried she will arrive early due to my cervix. But my doctor isn't sure whether that could happen or not. When is everyone else getting all the last minute but important stuff all done!!