Is it possible to retain some of the placenta/gestational sac until next period?

I miscarried at around 8 weeks (6 weeks after conception), but it didn't leave my body until 5 weeks after the miscarriage. It came out 2 days into what I thought was just a very heavy period. However, I'm now in the middle of my following period and on the first day it was very very heavy, and what came out looked a little like it could have been part of the placenta.... There was a tiny white/grey stretchy part in what came out, as well as some tiny dark balls of blood. Could this be some of the placenta or gestational sac that my body has retained between the periods (possibly as a consequence of taking the pill - so the hormones wouldn't let it out of my body, perhaps) ???

[AnnieBrooke]

It could be.   Once after my sister miscarried, she passed what she described as looking to her like a piece of chicken skin, several months later.