period and grad banquet... yay

so every year, my school hosts a grad walk and a grad banquet for all of the grade 12s graduating high school, and i'll be attending this year as i'm the graduating class of 2017! but the problem is... i will FOR sure have my period by then, and my dress is sort of tight fitting. so my question is, what kind of thong should i wear in order to wear a tampon, and perhaps a panty liner just in case? 😩😩 thank you!