You may need to go to a doctor if you are filling a super sized tampon in this amount of time. Do you have a General Practioner that you can call and ask if you should go in?
ru sexually active? there r lots of reasons y this may happen.If ur sexually active then it may be a miscarriage. if not then there r number of reasons y this may happen. its best to visit the ER or ur Dr ASAP.
Good luck and Keep us posted