I had the essure surgery 3 years ago and yesterday i started my period i put a tampon in and this morning it was gone there was only brown stuff and it smelled bad?

It is not "gone": The tampon is still in the vagina behind the cervix. Put your foot up on a chair or toilet which will shorten the vagina and make it possible for your to reach above the cervix and retrieve the "lost item" I you cannot find it see a GYN MD immediately, as the foul smell is a sign of infection and toxic shock syndrome can occur if the tampon is not removed.