First Baby

Hello! I am 18weeks pregnant, I was rather sick at first, so I lost a bit of weight. My body is changing, just no weight gain. My doctor hasn't mentioned my weight at all. I fly every week for work, I am on 4-6 connections for work and then to head home. My pregnancy was a bit of a shock, but we are excited as ever. I am so busy with work and travel I feel like I haven't done much for baby but head to appointments. When is a good time to start thinking about a shower, decorating, birth plans etc? Should I be concerned with no weight gain? I am a very healthy eater, and my doctor says he'd like to see me have 20 pounds total gained. I figured I was gaining and showing slow due to it being the first pregnancy? Any way done rambling🤗