I've been pregnant numerous times, and every time I've had plenty of people call me "hormonal." Unfortunately, it's pretty common to hear non-pregnant people talk about the hormones of pregnant women with reckless abandon and it makes us feel, well, crazy. Pregnant people need support, not accusations that make them feel like they're losing their mind, so it's worth remembering the things a pregnant woman hears when you tell her she's "just hormonal." Then it's worth, you know, saying something else or keeping your mouth shut.
From invalidating their feelings, to minimizing their reactions, to deflecting your own discomfort of someone's big feelings, telling a pregnant person she's "hormonal" is a big, huge, undeniable no-no. And for good reason. If you're close enough to said pregnant person that you get to have an opinion about her emotional state, then you should naturally be compassionate about the intensity of her emotions. Growing a human being is a lot of hard work, if you hadn't heard. The hormones that come with it are super intense. If you feel uncomfortable just witnessing the big feelings, imagine how she feels.
If you're not close enough to her to have an opinion about her emotional state then you should never utter anything even remotely close to her being "hormonal." Seriously. That is not for you to say. Ever. And if that makes you defensive, and you're all like, "But, I mean, this chick at my work...," or, "You don't know! You're being too sensitive!" then the following is for you. Because this is what you're actually saying when you say a pregnant person is hormonal, even if you don't mean it.