21 weeks is common for some pregnant woman for their belly to be small .. its fine , once you turn 28weeks / 32weeks your belly is going to be noticeable
I am 5 months as well and many commented that my bump is small. But I’m not bothered at all. Big or small as long baby is healthy!
I am 21 weeks. my doctor mention my baby is quite deep. so is okay if my bump isnt big. baby size is normal. dont worry
im 9 week 3day my bump size is like already 5 to 6mths but this is my 3rd baby lol
if its your first pregnancy its normal. my sil was fat and her pregnancy belly didnt show until very late
Don’t worry too much. It’s fine so long your baby is growing well inside your tummy 😉