Not sure how true this is but I remember hearing it on the radio back in the mid 90's where the local DJ was asking people who worked in ERs to call in with their weird stories. One guy called in and told a story about how this girl came in and said that she stank and was feeling sick. Upon examination, they found several tampons shoved up in her pussy. When they asked how this happened, she replied that she always had used pads and she was trying tampons this time. It turns out she thought you would just put another one in after several hours and they were crammed up there for days because she stopped bleeding.
Again, not sure how true but would it really surprise you?