Going camping while on my period :/?

I'm going camping this weekend, Friday night to Saturday morning. We are camping in a field behind my friend's grannies house, but we won't be using her toilet or anything, just roughing it and peeing in the nearest bush, etc. I'd be okay with this, except I know I'll be on my period. I use tampons every time, but you can only leave them in for 8 hours at a time, and I can hardly change it in a field lol what should I do, because I really want to go! and there will be guys there, which makes the whole situation even more awkward! :(