did your dog know you were pregnant before you did?

my "first born" doggo has always been a Mama's boy but as of late he has been so clingy. I walked out the front door to take the trash bins down and before the door closed behind me, he was whining for me to come back. as soon as I move he has eyes on me and if I leave the room, even for a second, he is right behind me. I have heard people say dogs can sense changes in hormones and act differently when you're pregnant because of the changes you go through. has anyone ever noticed this with their dog?