Psychic co-worker

I was talking to the  co-worker I'm closest with yesterday, and mid convo (about something else) I rounded my hands over my stomach. And immediately he says, oh, I know. I was completely thrown off because I just found out I'm pregnant this past Monday (I'm somehing line 4 weeks 5 days). I asked him how he knew (he's the only one I would tell at work before 3 months because I can trust him). He said that he can just tell. He and his wife have 3 kids so maybe that's how he can tell. He said he told one of his wife's friends at three weeks. So weird! Anyone else have people tell you you're pregnant or they know you're pregnant before you tell (and before showing)? FYI he's not actually a psychic or claim to be one. I'm just using "psychic" as a figure of speech. He could just tell.