Help finding a story

Years ago, I read a (fiction) story that I think was called "Nikki's Little Problem." It was about a girl getting a series of examinations for some reason. The part I remember most is that she had to get an ultrasound with a fictional device: A phallic probe that stuck up out of the table, which she had to sit down on, inserting it into her rectum. I can't find it anywhere. Strike a chord with anyone?

@brightyellow Is this the story you’re looking for?

https://storiesonline.net/s/39030/nikkis-medical-problem