I need period help pleasee!!!!?

Ok i have a really heavy period and im supposed to get it any time now and im going away to a camp and im leaving monday. for the first 3-4 days of my period it is really heavy and when i sleep sometimes i wake up and theres blood everywhere because it leaks out the back. i got some tampons for when we swim but im not going to sleep in them and i need to know how to go to sleep without getting blood everywhere, and i wear the super long pads and they are overnight but i dont want to have that happen and be embarrassed and have to deal with it