Disappearing baby bump?

Ok, strange question, but does anyone else have a bump one day and gone the next? I have more room in my abdomen than most because I have no stomach and very few intestines due to a gastric bypass surgery gone very wrong. I am 18 weeks 4 days and see all your cute big baby belly bumps and am so jealous! Only 2 days apart, green shorts was taken 7/05/2016, star's shorts just now 7/07/2016.