Please please please please please please please please HELP!!!!!!!!!?

omg i need help, QUICK okayy im going swimmin soon and i ave my period and ive never used a tampon before and i tried it but im really nervous and so i calmed down but it still wont work i cant get it i. i know TMI lol. anyway ive worn a pad the whole day today but its still white so i think my periods gone. but idk shud i still wear a tampon??? but i was planning to wear a pad and my bathing suit and then dark denim shorts over it jic. but idk im stuckkk what shud i dooo???