Gender reveal gone wrong??

So I did the sneak peak test and still waiting for the results and I am going to get a gender reveal ultrasound in august, now here’s my dilemma 😶😢 it says you’re supposed to be 14 weeks for the ultrasound but I will be 13 weeks exactly (this will be my first ultrasound) and I’m going to pay for it bc its at a private clinic, now I’m only wanting it to do it at 13 weeks bc my husband is coming home from a military training program less than a week after and I want to surprise him with the gender... so should I keep my appointment and hope they can tell the gender or reschedule? I’m conflicted 😐