My period was due on 21st,but still haven't got it,and i'm having a like brown discharge for 2 days,haven't had sex in over a month, cld i b pregnant?

Some thoughts...: Pregnancy is the most common cause of a missed period. If not pregnant, other causes of a late or missed period include: excessive weight loss or weight gain, increased exercising, emotional stress, having an illness, traveling, medicines (especially birth control pills), hormonal disorders, etc… A home urine pregnancy test is very accurate 3 weeks after sex.