I agree with the other ladies, you would be able to feel it. And also, after a few days it would have an odor. So I would venture to guess you are fine.
I use Nuvaring...and my concern was it getting "lost" in there. my doc told me there is no way it can get lost.So i would think a tampon wouldnt be any different. Make sure it isnt in there you should be able to feel it.
Odds are that its not there, but if it is you would be able to feel it with a finger and id recommend checking because of the risk of TSS. good luck.