Aunt Flow came to visit right before Prom

I'm not one to be into the whole Prom thing but me and my friends wanted to go to have fun because this is the last year I'll be with my friend and then this morning I wake up to you know who. So now I'm really need something that will stop it or lighten it or something. I get it very irregularly the last time I got it was May of last year. I don't use birth control. My mom doesn't let me use tampons so I just need something if anyone could help me it would be greatly appreciated. Thank You