Upset... Why can't I find out like other have many weeks before me!?

Emily
Made my 20 week ultrasound at 18w3d, ultrasound scheduling called me back to tell me I can't have it done until I'm actually 20 weeks. My dr told me I could get it done between 18-20 weeks. I told them that and they told me to call my Drs office and have the dr call them. Apparently I have a lot of time on my hands cause I don't have work, house to clean and a 2 year old to take care of. Needless to say I had to get their next available which isn't until Aug 16th. I'll be almost 22 weeks then. I'm so upset because I had a party planned for our gender reveal and everything and now I have to call it off 😩