First congrats! My daughter was born July 23rd, she weight 7 lbs. 15 oz. and was 19 inches long. She was only able to wear NB size clothes for about 3-4 weeks. She could wear the NB size pants the longest, but she outgrew most of the other stuff. It seems most of the name brands run large, so Carter's, Old Navy, etc. may last you a little longer size wise.Just get a few NB size items and a few more 0-3 size. You're right, even the Dr. cannot correctly predict the size your baby will be. Good luck