Early gender prediction?

We had our NT test done at 13w3d. It took the technician two hours to find all of the measurements...anyways in those two hours we had lots of time seeing the baby. The technician said she is technically not allowed to tell us the gender, we did tell her we really wanted to know. She was kind enough to give us a butt view and only said "that's not going away" 😁 my question would be if any of you found out this early (if yes when) or do both genders look too alike to tell yet? Thanks! 

Really excited about either one! ❤