Hello ? I'd like some advice, they scheduled two screenings at 20 week…

Hello ? I'd like some advice, they scheduled two screenings at 20 weeks. I wanted to have an ultrasound done at my private gynecologist's office, as it would be more comfortable for me than a service. Everything will be explained in detail. And in public hospitals, you know, quickly and all that. Has anyone had an ultrasound at 19 weeks and then a week later at 20 weeks?