I am sort of in the same boat- going to a birth centre but need to be prepared for the hospital too JIC. So I have packed according to three lists but they all fit in the one bag. Anything not used will just be unpacked when I get home but I think I have all covered. I had it done in a Word table and just have in bold what still needs to go in once contractions start and the list is on the fridge and my bag packed. The m/w at the BC told me the other day I need a clothes for me and bub to go home in (obvious I thought!), wipes for the baby and soap for myself!
Anyway my list:
Labour
• birth plan
• birthing notes
• lip balm
• pjs
• headband
• essential oils
• massage oils
• stress balls
• snacks- jelly beans etc
• toiletries
• face washer
• camera and batteries
• socks
• waterbottle
• juice

Hospital/BC post birth
• mobile phone
• phone charger
• pjs
• day clothes
• slippers
• toiletries (lansinoh, toothbrush, paste, moisturiser, deodorant, body wash etc)
• makeup
• facewasher
• maternity pads
• breastpads
• notepad and pen
• wetwipes
• knickers
• tissues
• maternity bras
• socks
• hairclips
• money
• watch
• reading material
• bag for laundry items
• snacks (muesli bars etc)
• drinks

Baby
• singlets
• suities
• wraps
• socks
• hat
• cottonwool pads
• blankets
• wipes

I hope you like my list as much as I do!
I just have the labour stuff in separate bags in the big bag to get access to quickly!