Need advice!!

So I'm 16 weeks pregnant and haven't had a single ultrasound yet, but I was told that's normal by my doctor so that's fine I guess. Anyway, my first one is coming up on the 26th, but not the one my doctor booked, it's a private one where they'll tell me the gender and I'll get a little video of baby moving around. They ask that you bring a snack that you know your baby will react to, but I haven't even felt kicks yet so how am I supposed to know?? Any advice helps😅