Help !

So I have never used tampons before as I just can’t get them to work with me, I would love to use them so I could go swimming and stuff when on my period, but anyway..

my period is late by like 3 days (says this app), but I’m kind of irregular all the time anyway, but on the 10th of April I’m going overseas to SE Asia and obviously we will be spending a lot of time swimming and all that kind of stuff, and I have tried to do my calculations and today It had been 30 days since my last period and so I’m just not sure what to do?

Haha most of the time I’m wishing I didn’t have my period but now I WISH i had it now !!

Help ! 😩