What is your experience?

Each pic was taken around 17/18wks in each pregnancy. ~ First baby(girl), I started showing around 13wks, Second baby(girl), I started showing around 9/10wks, now here I am pregnant with my third baby(sex unknown) and I'm still not showing.(that "bump" is my mom pouch from my previous pregnancies). ~ I know every pregnancy is different but this one is so strange, I'm not showing, no baby kicks or "quickenings", this time I've only gained 15lbs so far(in total my first i gained 90lbs, second I gained 60lbs, and by this tine in each i had gained 30+lbs). ~ Is it so different because it could be a boy?(HR is 155 if that means anything towards boy or girl) What other reasons would this be so different in how I'm carrying and presenting? Am I doing something wrong? Does this mean I mifht have a premie baby because of how small they are and me not showing? ~ You'd think I wouldn't be concerned being my third pregnancy but it's just SOOO different compared to my last two, which is also funny because at the time with my second baby my symptoms and cravings were so different I was convinced she would be a boy but turned out a girl. But now symptoms and cravings(or lack of) are different, and how I'm carrying is so different. ~ Thoughts? Opinions? Anyone go through this and what did you have?