Period during camp, and running a lot?!!?

well my field hockey camp starts on july 28th. :: well i started my period July 1st and ended July 4th. I really don't want my period during field hockey camp on July 28th and I really don't want it during vacation at california when were leaving August 8th. Please help i've been worried about it ever since i started my period that day! and i don't want my period on the plane ride that would be really uncomfortable and uncomfortable during field hockey camp. I think I have a regular cycle. But i don't know yet. I don't know what to do and I don;t want to take Birth Control and I don't thin my mom would let me. please Help.! i hate my period so much cause it's always heavy for three days.-_- and can anyone tell me what to do if i do get my period on vacation or during field hockey camp. cause i don't like wearing tampons when my period is heavy cause they always leak through and I don't think I would have time to change it every 2 hours. My sister told me that during field hockey camp she had to run a lot and she was very sore and I really don;t like running on my period and I can;t cancel that.! please help): thiss camp is from 8 AM - 8 PM and i dont know if i will have time ot change my tampon if i do get my period. and i really don't like wearing tampons either but i don;t like running a lot with pads either. helpp i am soooo worried. and the 28th is the day i will get my period ans this camp lasts for 3 days. and my period lasts for 4 days. D: i can't take any pills either. :( anybody... please help.! i am stressing out!!