Does my dog know that I'm pregnant? He's a two year old golden and he loves me and all but really…

Does my dog know that I'm pregnant? He's a two year old golden and he loves me and all but really takes to my husband a lot more. I get kind of irritated with him so he sort of stays his distance most of the time. Am I depriving him the opportunity to even learn that Im pregnant or does he still know? I've heard dogs can hear baby's heartbeat through my stomach