I Got The Depo Shot On December The 14 For

I got the depo shot on December the 14 for the first time m. I usually start my period on the 1 and I just not started to spot.. today is about the 2nd day I've been spotting and I pulled out my tampon and a large piece of skin came out.. it resembled like a worm but I moved it and saw it looked like a thin pieve of chick skin.. I'm so scared I don't know what it is .. I haven't had sex in 2 months