Period help for a 14-year old?

Hi. Well, I just got my period yesterday. The thing is, that I am driving to North Carolina which happens to be 12 hours away. I don't want to be like "Hey dad, can we stop and go to the bathroom for the umpteenth time today?" while were driving. And, of course, when we get there, I can't swim in the ocean because i'm terrified of sharks and, yeah, blood+sharks= death. So, anyway, is there anyway I can lessen my period for the car ride? Or maybe for the ocean? Thanks in advance, Alex