I had about 4 packs, and used up half a pack for when my waters broke, and the rest after the birth. I also found that the thicker ones 'felt' better... more secure and comfy for those raw/sore areas. Although not so good when going out in public wearing jeans or something, as I was always paranoid that they were too bulky iykwim, lol.
I cant remember too well, but I think I moved onto Goodnights pads after the first week, and normal pads after the 2nd week. Although I did bleed on and off for 10 weeks after Aidyns birth.