I'm 5'4 and weighed about 135 before I got pregnant and I started showing right about the beginning if 17 weeks, nothing huge but if I wear a tight shirt you can tell it's a bump!
First off its literally impossible to show at 5 weeks, your baby is the size of a sesame seed and weight and height really have nothing to do with it, it all depends on where the baby is positioned, my sister was 97 lbs when she got pregnant and she didn't have a noticeable bump till she was 7 months, I was 100 lbs and I started showing at 5 months, my best friend is pregnant and she's like average 125 lbs and she is 34 weeks and barely has a bump and another friend of mine was 118 lbs and she started showing at 17 weeks so honestly it's different for everyone. Most don't show till about 17+ weeks
I'm 5'6 nd prepregnancy 115 nd I started getting a lil bump at like 22 weeks and.noticeably at low 27 weeks it can take a while if its ur first
shyou can a big bump and a small baby. and also all it is water weight . my sista stomach meduim size and all my necis n nephew was at aleast 7 or 8 lbs
First time moms usually dont start showing till about 20 something wks I think ur friends r just bloated at 5wks the baby is the size of a sesame seed goodluck :)