I hadn't my period this month it 20 days late now.. i got brown discharge.. i did urine pregnancy test it was negative what is that?

Probably normal: Some women will have irregular periods. Keep track of your cycles for the next few months, and report to your physician what is going on.

Brown Discharge is: usually old blood being cleaned from uterus.Reasons for missed / late period include: an anovulatory cycle in which no egg is released, marked v or ^ in weight; eating disorder; Over-exercising (endurance athletics), stress, travel, significant illnesses, oral contraceptives & other meds, Illegal drug use, breast feeding, hormone imbalances and medical problems (i.e., PCOS). Pregnancy is #1 reason