I'm 7 months and people ask me all the time if I'm 4 months. Some women are just smaller than others as long as you are measuring correctly when you go to the doctor thats all that matters
With my first child I didn't show until I was 30-35 weeks pregnant no one could even tell I was pregnant now i am pregnant with my second i am 19 weeks tomorrow and I already have a bump
I didn't start showing till I was like 25 weeks but I'm 4"9 and weigh like 98lbs now I'm 33 weeks pregnant n so far I only gain 20lbs this is my second baby my first baby it was the same as well n she came out at 6lbs n 3oz perfectly healthy