Baby bump

Any body else feel like some days their bump has gotten smaller? Is that normal? It worries me because I’m 19 weeks and I know it should be getting bigger by the day, but there’s times I look in the mirror and feel like it’s not as big as it was before. Maybe due to bloating? Has this happened to anyone else? I go for my anatomy scan next week but I just can’t help but to worry maybe the little one stopped growing :/