Lost my necklace.. Karma/curse?

I had my tiffany's necklace on my desk on thursday, & then on saturday i went to my desk to put it on and it wasn't there... I searched my entire house and no one took it, as my siblings aren't home & none of my friends have been in my house so they couldnt have taken it either.. Do you think this disappearance could've been karma or a curse? my ex-bestfriend that hates me used to practice witchcraft... if that helps .