3D/4D ultrasounds?

Did anyone get a 3d/4d ultrasound? I can hold out until 20 weeks to know the gender, but the DH is willing to pay. Just wanted to see if any one could tell the gender before 20 weeks anyway with those & how far along were you?

Oh, and also where did you go? We live in Denton, so Dallas, Southlake of Frisco are the places I have found so far.