I usually have a 21 day cycle, i was 5 days late and bled for 2 days normally, then stopped for a day, now spotting, could i be pregnant?

Probably not, but...: Many women have occasional variation of their mucus discharge, spotting between periods, a heavier period, a lighter period, or a late or missed period. Causes include: excessive weight loss or weight gain, increased exercising, emotional stress, medicines, having an illness, traveling, birth control pills, hormonal imbalances, etc… if worried about pregnancy, one can do a test 3 weeks after sex.