STILL NOT SHOWING

Today my mother in law asked me how far along I am and when I said I was 4 months she then proceeded to google pictures of other pregnant women who were/are 4 months along and said "this is how a belly should look at 4 months". Then she told me that her other daughter in law was already showing by now and had a big bump at 4 months. Should I be worried that I'm still not showing 
(I'm a ftm)