Can your other young children sense that you are pregnant?

Robyn
I have a 16 month old and she has been acting differently the last few weeks.  I am only 8w4d along but I was wondering if maybe my daughter is acting out a bit because she senses things changing with me?  Or maybe I am reading too much into it ad she is just picking up on me not doing as much with her because of my fatigue and nausea?