The best thing you can do is squat on the floor, insert two fingers, bear down as if you are going to have a bowel movement, while bearing down sweep the area with your fingers until you either find the string or can pull on the tampon itself. If you don't get it your first time, that's OK, just relax and bit and then try again. Also do make sure to wash your hands well before and after. If you still can't do this after a number of tries, then you may need to go in to get it removed, but by doing the above, you should get it.
Best of luck, Hope this helps, If you need anything else please feel free to ask. If you found this helpful don’t forget to click the *accept* button!
