You can’t lose a tampon inside your body. It is not possible. However, it is possible to lose the string. Even then you can remove it. Do not panic if you forget a tampon inside you. The tampon usually gets compressed at the top of vagina. Try finding the string of tampon and pull it out. If you can’t find the strings go to your nearest GP or ER so they can pull it out for you. Do not wait for the next day to begin especially when you have pelvic pain, fever and/or smelly vaginal discharge. A rare but serious condition of Toxic Shock Syndrome is associated with tampons. Always remember to remove the tampon after 8 hours.