text: When you first start out having periods they are sometimes irregular.   I don't know how many days you usually have your period.  Most girls average 3 to 7 days.  So I'm guessing that the worst part of your period will be over with and hopefully that will mean that you will be having a lighter flow by the time you dance.  The "pill" though good at regulating your period can have side effect.  Don't let your period ruin you trip, have fun anyway!