Girls, help plz??????????????????????

okay so im going to a water park tomorrow but i am on my period like normally its only 3 days..it's been 3days but i'm still on it.. The problem is i haven't told my mom about my period or anyone for that matter i think we have pantyliner but i'm not sure...and i wear shorts over my bathing suit.and we dnt have any tampon's so what should i do