2d/3d/4d Ultrasound Scan for Gender

I have an appointment set up with a private company when I'll be 15 weeks. I didn't do any genetic testing, so no blood test to confirm gender even earlier. My OB will do the official gender/anatomy US when I'm 20-22 weeks and I didn't want to wait much longer. Anyone have accurate results at 15 weeks? They offer a free recheck whenever you want it, so I'll be able to know for sure. I just want to know if you guys knew for sure at the first one. Thanks!! 😊