I'm 17 days late am i pregnant?

Maybe. Maybe not.: In a woman with regular periods, some causes of a late period include: excessive weight loss or weight gain, increased exercising, emotional stress, having an illness, traveling, medicines (like birth control pills), hormonal imbalances, etc… Pregnancy is the common cause of a missed period, if sexually active. A home urine pregnancy test, done correctly, is accurate if done 3 weeks after sex.