Oh, I misread the OP. I had a morph scan done at 18 weeks and that confirmed the sex. The 4D scan that I paid for out of my own pocket (its elective), was done at 28 weeks and confirmed once again.
At 33 weeks the OB did an ultrasound and DS was in a comfy position showing off impressively sized private bits.
So I had it confirmed 3 times. Though the 33 week U/S was pure luck as it is nearly impossible to see the sex at that gestation because bubs is too big.