When will I find out the gender?


I’m currently 12 weeks and I have 2 appointments on the same day in early September. They said one is “pregnancy visit” and one “nurse visit”. I will be I think 15 weeks at that time. Will they tell me the gender at one of those appointments or will I have to wait for my next appointment the month after? I’ve heard a lot of people find out the gender at 15 weeks. But my doctor hasn’t said anything to me about when we will find out.