I'm 29 weeks and just packed my bag this weekend, mainly because a friend who is also 29 weeks was rushed in to hospital for a few days and didn't have anything prepared.
For the baby you want a few outfits, muslins, a swaddling blanket, hat, mits, and car seat.
For you: night gown, slippers, flip flops for shower, big knickers, maternity pads, nipple cream, lip balm, hair bobbles, comfy clothes, phone charger, a spare pillow if you want, maternity notes, birth plan, wash stuff, tooth brush.
Maybe a book or something. I was in for 4 days with my first and it can get a bit boring.