I didn't get my periods this month, its 16 days past from my due date for periods. I am seeing brown thick discharge from last week. What's the problem?

Pregnancy test. Hi, the most common reason for missed period in sexually active women is pregnancy and its complications, you need to check a pregnancy test, if negative then there are other possibilities like stress, anorexia, excessive exercise, excessive weight loss, polycystic ovaries, hormonal imbalance, please see a doctor for evaluation.