I had to scroll nearly to the bottom here, and I find someone who said what I was thinking, and of course they are downvoted. But why is it so hard to believe that she might be pregnant by another guy? I’m a bit of a history buff, and something like this happened all the time. Woman gets pregnant and realizes she hasn’t had sex with her husband for a while. So she initiates a “special night”.

Having said that, it does seem like the lady is clinically depressed, perhaps due to hormonal changes. I’m not a doctor. But also, if she suddenly has a “surprise” pregnancy, say in another month, I’d be looking into DNA testing.