An Olympic swimmer raced with her period and a lot of people are really, really confused.

After swimming in the final of the 4 x 100-metre medley on Sunday, Chinese swimmer Fu Yuanhui squatted alone for a moment, with her hands clutching her abdomen.

When the poolside interviewer asked if she was okay, Fu responded; “I feel I didn’t swim well today. I let my teammates down…Because my period came yesterday, I’m feeling a bit tired, but this is not an excuse.”

Fu is of course one of our favourite athletes of the Rio Olympics, ever since she discovered mid interview that she had, in fact, won a bronze medal.

WATCH: Chinese swimmer Fu Yuanhui finds out about medal win in post-race interview. https://t.co/CiWhn2HrPM #Rio2016 pic.twitter.com/Sc59VeAWJH

— 7Sport (@7Sport) August 10, 2016

The Huffington Post labelled her ‘The Most Loveable Athlete’, and we swiftly agreed.

Fu Yuanhui tells the world she's on her period after mediocre performance in swimming relay https://t.co/YG0pdX7nTN pic.twitter.com/uYBjxm5q5i — Shanghaiist.com (@shanghaiist) August 15, 2016

Fu was careful not to use her period as an 'excuse' (although, in our opinion, it's a legitimate one) continuing, "... it happens and you're dealt with different cards on different days and I should have dealt with it better. It's a real shame and it sucks."

And haven't we all been there.

But Fu's comments were only the beginning.

Many Chinese viewers took to Weibo, a social media site much like Twitter or Facebook, to express their confusion.

"Why was there no blood in the pool?" One commenter asked.

The hashtag #FuYuanhuiperiod then began trending.

Within a few hours, the search terms 'Fu Yuanhui period' had been entered half a million times.

And there was a reason why so many people in China were so fascinated by Fu's admission.

For some, this was the first they had heard of tampons.

Last year, Chinese manufacturers made 85 billion sanitary pads.

They didn't produce one.

China's first tampon brand is expected to launch later this month.

According to Quartz, Chinese culture places "a high value on virginity" with many Chinese women undergoing hymen restoration surgery. It is believed that tampons interfere with a woman's hymen, and therefore tampons are not introduced into sex education.

For many Chinese women watching the interview, Fu's comments were a revelation.

In the past, we have reported how American women are "completely freaked out" by Australian tampons. It would seem that us women, despite having a pretty similar period, are dealing with them in very, very different ways.

Fu isn't the first female athlete to reference her period after a sporting performance. British tennis player Heather Watson said “I think it’s just one of these things that I have, girl things...” just after losing a first round match at the Australian Open last year.

For half the population, including many Olympic athletes, periods are a fact of life. And sometimes they bloody (pun intended) suck.

Good on Fu for talking about hers. And as a result, introducing the tampon as a talking point in Chinese culture.