Major period help?? please girls i need help?

ok...i am 14 years old and had my period for about 1 1/2 years now....i get my period for about 5 days. Today is my 32 day and i still didnt get it yet!!! I dont have or anything like that so im not pregnant.....and the sucky part is that this friday i am going upstate with my family and another family and we go swimming in the river and stuff and if i dont get my period today then it would suck not to be able to go in...i dont use tampons.....what should i do??/ And if doesnt even feel like im getting it soon cause i usally have cramps to warn me when im about to get it but i didnt get cramps yet?? what do i do...help please