What Are The Side Effects Of Emergency Contraceptive Pills?

Hi there. I've been on the pill for a while now and I skip my period by skipping the inert tablets and going straight to a new pack. I've skipped my period about five times now and I've decided to let my period go on. What's worrying me is that there was a long piece of skin that came out when I was changing the tapon today. It was like whitish with blood and about 5mm thin, 7cm long. I am worried. I could describe it as a mini umbilical cord? What is happening to my body? Could I have been pregnant but I didn't know? Do I have a disease?