Yep! They can sense it..

my daughter just lays on my tummy and when she sees her dad she says daddy and puts her hand on my tummy..it's just weird

with my first kid my nephew told me i swallowed a bahy seed before i knew and now im pregnant again and the week i found out my 1 year old daughter was super clingy to me

my little brother said I was pregnant before I found out I was so yea kids just know that stuff

my son knew before I did he started to more over protective won't let anyone around me and he started to just want to sleep on my stomach and one day he said "mommy you have baby sister in tummy " and I took a test next day came out positive and also found out I'm having a girl