Am I about to get my period?

It’s skipped for the last two months, and lately I’ve been slightly suspicious. I’m not pregnant, (Im a virgin.) and for the past couple days, I’ve had a decrease to almost no vaginal discharge. Mind you, I’m only 14.. Not only do I have this to worry about, but I leave for camp the day after tomorrow. It’s mandatory to go swimming, and I’m scared to use a tampon because I can’t leave it in for more then 6 hours. Friends at school say that when you stop getting discharge, you’re about to get your period, and I’m kind of scared. If I don’t take part in the activities, then kids will tease me. And also, I’ve traced back to my last period, and counted up the days to when my next one was supposed to be, and according to those calculations, I’m not supposed to get it until the end of the month.

Should I just stop worrying about it? If I stop stressing over it, will it maybe not happen during my camp week? And if it does happen, what can I do? My mom says to just stop thinking about it, and that it won’t happen, but I’m not so sure…