Im going to Vegas while on my period?!?!?

Okay so im going to vegas in 3 days and im period started on... i forgot .. i think june 30 or june 28 or somethin.. anyways, my period is still unregular. So im going to vegas and everytime we go, we swim cuz its blazing hot there.. but what can i do if my period doesnt stop??? I dont want to use a tampon cuz this is like my 3rd time having my period and to be honest... i dont know where exactly your supposed to put a tampon.. i mean yeah up your vagina hole, but i dont know where that goes...lol SORRY. soo yeah, tampons are off my list, Anything i can do??