Finding out gender later than expected

Alli • Grace 10-8-18 ❤️❤️

I’m 14w3d and had an appointment on Monday. We heard the heart beat and he said we would do another appointment the same in 4 weeks (18w) and then 3 weeks from there (21w) they would do the anatomy scan and find out the gender. However a bunch of my friends are pregnant right now as well and they all have or will find out the gender around 18 weeks. I’m surprised they’re making us wait so long. Is that normal? Do you think I could ask to have it pushed up even to 19 weeks? 21 weeks is another 7 weeks and I’ve been dying to know since my first ultrasound at 8 weeks