How much weight will I lose during childbirth and the days following?

Tomorrow I will be 37 weeks pregnant, and have gained 14.5 pounds so far. Hopefully I will gain below my goal of 18 pounds. In the last two weeks I have stopped running, but am still doing some core and lifting, so hopefully my abdominal muscles will bounce back pretty quickly. But does it even matter how strong your transverse and rectus abdominis are when it comes to how quickly your belly bounces back-- I dont even know?! :) This is my first creation. I have heard you lose half the weight; but I am hoping for more...If I gain around 16, is it possible to 11 or 12, so I only have 4 or 5 to go??? I know everyone is different, but I would like to hear from a fit mamma who gained 15 - 20 lbs. Thank you!!!