I'll probably wear it regardless (mwahaha,) but I wonder if it's that un Orthodox? Despite the fact that it's a RC devotion, what's wrong with an Orthodox Christian wearing it?
The inscription is: "O Mary, conceived without sin, pray for us who have recourse to thee". Since I've read numerous times here that everyone is conceived without sin that shouldn't be a problem. More problematic is the image: no Christ, no three stars of ever-virginity, Sacred and Immaculate Hearts portrayed.
Honestly though you don't know by now some posters will say its ok to keep but not wear and some will advise getting rid of it so you don't get Catholic cooties?
Many of my friends wear a St. Christopher medal but yet they are non-church attending protestants. I have never seen any of them melt, burn up or receive the plague from doing so.