"So I just opened it up, what is that?" she asked, as she took out the strange metal object.
The now-viral video has since racked up 8.4 million views and nearly 9000 comments from concerned followers.
"My brain instantly said tracker" someone said.
"Imagine some younger girl not knowing that isn't unusual and using it" another commented.
"I know accidents happen, but women already have enough to worry about."
"I'm scared" said another commenter.
"Stay safe ladies."
In a follow up video, Celia explained that she did not actually buy the box of tampons from a store, but claims her friend who works at the Tampax factory gave her some directly.
"Tampax send me a prepaid mailing bag to send them the tampon and the contents" she said in another video.
"Then they included a letter from Tampax saying that they were going to send me compensation, I was not expecting that, I don't know what that entails.
"I only posted this video, because if someone who was inexperienced got this in their hands, and didn't realise there was something wrong with it, and they started to use it, I feel like that's really scary.
"This should not be happening, no matter if you were given it or if you bought it, it shouldn't have left the factory. It doesn't matter how I got it in my hands.
"I think that's the main issue here."
Many people speculated that the metal inside the tampon was part of the testers and possibly slipped through accidentally.
"It looks like it could be a defect detection tester?" someone commented.
"So they put it in on the line to see if their quality control system picks up that it is defective."
"The 'SS' is for stainless steel. It's non magnetic and harder to detect."
A spokesperson for Procter & Gamble, the owner of Tampax, said: "We are aware of the TikTok video and are looking into the matter. This is a sample from our quality control process we believe was accidentally gifted from an employee to a friend. Quality control samples are not sold to consumers."