Its normal! Not every girl shows at 18 weeks don't worry once you get further along your belly will pop out.
I didn't show until 32 weeks!!! Every girl is different :)
My sister has 3 kids and you couldn't tell she was pregnant untell the last one and even then she just looked overly bloated all her girls were perfectly healthy and normal size
With my son I did not show till 7 months with this one I'm 11 weeks and I'm starting to pop
My first I didn't show until 6 months my second and now third I started showing before i even knew i was pregnant! Each pregnancy you show quicker
Thanks, this alleviates any concern I had c: