I Need Help?!? Girls only please?

Hey! So, I'm going on a retreat with my church for a week. The leader is a boy. I think we are having a girl leader come too. But I'm going to be having my period while I'm there! I ONLY use tampons btw. 1 day, we're going to a water park the whole day! And the rest, we'll be outside doing fun activities (A lot include water fights etc.) Any advice?? Thanks!!