Best idea to pack now. You won't know if suddenly you need to be admitted early. I'm a mother of 5.
Just bring your I/C, hp charger, socks, jacket/cardigan. Just the essentials and not the unnecessary. Go light, cos you'll be going home with many things in hand, your baby, your bag of medicines and probably the hospital's goodie bag. Pads, baby diapers are provided by the hospital.
Also breastpump is always not needed. You'll be ask to latch baby unless baby is in NICU, then formula will be given. All the best!