Looking for advice, what is this I passed today? Uterine lining

So I'm due on my period but I'm a few days late. I'm on the pill (the one you take for 3 weeks then have a week break) been on this pill for 3 months

Nurse's TikTok Explains 'Decidual Casts' – When Your Uterus Lining Sheds Whole

What Causes Endometriosis? Genetics, Immune System, Menstruation

I Got An IUD And This Is What I Learned

The menstrual cycle Office on Women's Health

Endometrial biopsy: 5 things to expect

4 weeks pregnant: Symptoms, tips, and baby development

Menstrual Clots and How They Are Linked to Endometriosis

Opinion Early Abortion Looks Nothing Like What You've Been Told - The New York Times

The Uterus: Anatomy and 3D Illustrations

Uterine Fibroids: Causes, Symptoms, Types and Treatment