The gold medalist and "Dancing With the Stars" finalist laughed off the unexpected guest from the World Anti-Doping Agency, charged with collecting samples at random times to ensure competitors don't use prohibited performance enhancing drugs.
"They haven't tested me since the Olympics, and they choose the final week of 'Dancing With the Stars to come!" she told hosts Billy Bush and Kit Hoover. "Out of all the days since they Olympics, they choose like, the craziest week."
Although the random nature of the tests can be inconvenient, Raisman said she doesn't really mind.
"I'm clean, so I don't have anything to worry about," she said.
Plus, she said the test, including a urine sample, wouldn't take long -- "I just drank a lot of water," she told the hosts with a laugh.
Raisman confirmed she would be back to compete for a spot on Team USA for the 2016 Olympics.
"Yes, I'm in," she said. "That's why [the tester] is here!"