Hospital bag.

How early should I prepare my hospital bag? I'm 6 months pregnant right now. I have a 2 year old toddler. My husband works shift hours and is always at sea. He works in the marine industry. It's only the 3 of us living together. All our family members live far from us. In case anything happen to me(suddenly abt to give birth etc) while hubby is alrdy at work and out at the sea, how early should I strt packing my hospital bag so it's easier to just grab and go in case those scenarios rlly happen?