I thought big knickers were granny pants. No, big knickers as in the ones that come up to your boobs and down half your leg. The most massive knickers you can find, 2 sizes bigger than usual.
I had emcs. I didn't have massive knickers. When they made me take the dressing off, my incision was positioned in the perfect place for my knickers to rub.
Otherwise, my labour bag didn't actually make it out of the car until after my baby arrived.
I didn't have enough blankets. And talking of blankets, we have loads of posh, thick, colourful, expensive blankets which are all useless.
Those £3 cheap cellular blankets are all you need trust me. Good for swaddling and layering. All his thick, beautiful blankets are still in his draw and have never been used and he is now 4 months old.
I ended up being kept in for a week so had to send the partner out for supplies. Make sure he knows where everything is at home.
Anything you forget you can send someone to buy anyway.
Good luck