How do you know if you're having a boy or girl? Before having that ultrasound, of course.

So different cultures and old wives' tales have different ways to determine the sex. I'm wondering what y'all have heard and if it was right. My boyfriend is Arab and last night he wanted to bet me that we were having a boy. I really don't have a feeling either way so I asked him how he knew. He said Arabs have a saying that if your pregnant with a girl, she takes some of the mother's beauty to make her own. But a boy will only add to the mother's beauty, so that's how he knows. Isn't that adorable?! 💘👪