Hello girls, we're going for an ultrasound at 12 weeks and 3 days. We …

Hello girls, we're going for an ultrasound at 12 weeks and 3 days. We would like to know the baby's sex beforehand. They will say it's not 100% sure, but is it really possible on a good machine to see the sex at least preliminarily? I am more worried that the baby will be healthy, we are going to a private clinic, our doctors haven't even scheduled a screening yet! They say from 11-14 weeks?