Not saying I know exactly how it works in Georgia - but if you were my state it may not be too late. You'd have to take some action *now*, though. In my state, to get birds tested for a show, you need to have a Certified Poultry Technician do the cloacal swab on the waterfowl. They drop the swab in a tube, band the bird, and mark the tube. The poultry tech will then draw up the paperwork and submit everything to a Diagnostic Lab for testing. Provided that your waterfowl come back free and clean from disease, you would receive clearance papers that you would take with you to the show and provide when you coop-in your birds.
You said they were going to have a tester on site? Hmm. To me that almost sounds as if they are going to have someone there from the Dept. of Agriculture randomly checking the birds. But, I honestly have no idea how the law runs in your state. What poultry club is putting on this event? Do they have a website? They are going to have a deadline on entries. Typically you will need to enter for the show via online or snail-mail. The club will provide the entry form for you, and they will also attach a copy of what health testing requirements are needed prior to the show. You can also find out who they suggest for testing and when you need to have your entries in. I'd give them a call!
Edited to fix spelling errors; ugh. too early!