Postpartum things to pack in hospital bag.

Hey guys, I’m currently 33 weeks pregnant and I’m starting to pack my hospital bag. As I’ve packed some stuff like toiletries, slippers, comfy clothes... people have mentioned to bring postpartum underwear or pads etc. I’ve packed some pads and some “granny” panties. But I’m not sure on what postpartum underwear is or where to get some. Also is there anything else I’m forgetting or that’s a must have after giving birth!!! I’m a first time mom and I’m clueless soo all the help would be great!!