Can babies tell if you're pregnant?

Madi • Mama of 2 🌿 Artist. Nature. Salt Lake. Moonwoman 🌙
My daughter is 1.5 and has been EXTREMELY clingy the past few weeks. She won't let my boyfriend (her dad) pick her up if I'm around, she loves her grandma's and aunts but won't even play with them or go to them if I'm holding her, she gets upset if I leave the room she's in or even if I go to the bathroom without letting her come in. 
For some reason I'm thinking it's related to me being pregnant? 
Do you think babies/toddlers can sense pregnancy? I'm only 4 weeks 5 days pregnant, so it's not like I look different or anything, and I'm barely having any symptoms so I don't think it's because she thinks I'm sick...
Not complaining lol, I love my snuggle buddy, it's just making my family and boyfriend upset because she doesn't want to be around them when I'm there and I feel bad.