Spotting on my period for two days why?

Some thoughts...: Many women have occasional variation of their mucus discharge, spotting between or in periods, a heavier or a lighter period, or a late 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 having sex, pregnancy can be the cause, so check a home urine test.)