can your toddler sense you're pregnant before you know?

Mimi • Momma bear 🐻 expecting her second cub💙.
So I have a soon to be 2 year old and he started pulling my shirt up and putting both his hands on the side of my belly and saying baby/ kissing my stomach or just putting his head on my belly and rubbing my stomach! I just got two negatives last week though. Can babies or toddlers sense you're pregnant or about to be?