Hello, I Have Been On The Same Contraceptive Pill For

Hello, I have been on the same contraceptive pill for five years and never had any side effects. Yesterday I started bleeding unexpectedly which has never happened before. Today I suffered severe cramps which I have never suffered from before and this evening I passed a thick white tissue like substance that looked and felt similar to raw chicken and one end of it looked bloody. Can you please tell me what this could be.