Can you wear a tampon when your not on your period?

My period was suppost to be here on friday. I'm suppost to go swimming with my friend, but I don't want to start my period at the pool. My mom said I could just just wear a tampon, because 2 hours won't hurt even if I don't have my period. I told her I was scared of getting TSS from that, but she said she even does it sometimes. Would it be ok if I wore a tampon for 1-3 hours and i wasn't on my period? Because I might start it and I don't want to get it while Im at the pool. Thanks in advance!