I Just Woke Up From A Nap. Changed My Tampon

I just woke up from a nap. Changed my tampon and 2 peices of skin, together make about the size of my palm, not to bloody, pretty thin, not at all chunky. But they were defenatley skin. This has never happend. This is my first period since I started birth control. But I have taken this birth control before and this never happend. I have 2 kids a 3 year old and a 4 month old. Idk if that info helps at all.