Treated different at work bc pregnancy?

Ok I am curious about your thoughts and experiences about this. So last week, most of my coworkers found out I am pregnant including this guy that works underneath me. Since then he has been rude and cold towards me, whereas before, he was always easy going and pleasant to work with. For example, since he found out he sent me a reminder email in all caps and later sent me one cc’d my boss where he was complaining about my almost missing a deadline.

Recently, I had 2 other coworkers quit and I’m basically busting my ass to cover for their absence since we haven’t had anyone fill in yet. Luckily, my managers of course understand why I’m not able to meet every deadline but why is he so rude all of a sudden?!