I just noticed a quick way to tell if your sim is pregnant. Click on their phone. If they are pregnant, the "enroll in university" option should be grayed out. If you move your mouse over it, you will get a little message saying "(sim name) is pregnant." I don't know if this is common knowledge and I'm just being stupid, but I thought some people might like to know.

I always relied on the bells that ding when a try for baby attempt is successful, but that's a nice observation about the phone and Uni.

Risky Woohoo mods usually disable the bells. Also, Try for Baby should no longer be an option if you're pregnant, so that's probably another way to tell.

I just check to see if the little moodlet is there.

That's really interesting Krinci! Didn't know that haha. I usually like my pregnancies to be a surprise, and it'd be pretty cool if our sims could go to university as a pregnant student.

I'm under the impression that the method is to reveal whether a Sim is pregnant before the moodlet shows up.

Other than enrolling the university, the game doesn't allow you to travel abroad too, so that's another hint.