omg, i reali dont suggest poking ANYTHING but urs fingers around in there! u cud tear sumthing or give urself an infection. u need to make an emergency trip to ur GP or even A&E.
If u leave it in there for much longer u cud contract Toxic Shock Syndrome (TSS) which can make u infertile or can even be fatal. seek help ASAP
A minor emergency clinic could help you. They get this every now and then, so don't be embarassed.
Or, I suggested this once before on the site and peek nearly had a heart attack, but there are also really big, fat, plastic crochet hooks for using with that huge fat yarn (think: as fat as child's chalk) for sale at knitting shops and fabric stores, that can be sterilized (boiling) and used to fish for the tampon string. DO NOT TRY THIS WITH A REGULAR CROCHET HOOK, ONLY THOSE FAT BLUNT ONES MADE OF PLASTIC THAT WON'T POKE OR SCRATCH YOU, AND DO! BE SURE IT IS STERILIZED, if you try this route.
All in all, a minor emergency clinic is easier. LOL