Planned Gender Reveal party for the wrong date!!!

I had my first ultrasound in my OB's office so I thought the big ultrasound would happen there too. Ugh!!! Just found out that we have to wait another week after the Gender Reveal Party in order to be covered by insurance. So, my options are to reschedule party OR spend $85 at a local Ultrasound facility to find out the same week as party. What would you do?!?!