I started back on NuvaRing the beginning of May after having my daughter a year ago and breastfeeding until April. I took it out on the 25th asdirected and I started my period today. Very bad cramping. Tonight while changing my tampon I passed what I thought was a hugeee blood clot. When I looked I noticed it was roundish and white/grey kind of shriveled with a little bit of blood. Bigger than the size of a quarter.