What Causes Abnormal Bleeding And Painful Cramps After Removing Nuvaring?

Ive been using the nuvaring and recently i took it out for the week I'm suppose to, to have my period. Im use to it taking a few days for my period to start and when it did it was the normal painful cramps, Until i went to the bathroom and saw a sack of some sort that came out of me. Was i Pregnant and was this a miscarriage?