Have Been Experiencing Slight Bleeding With Bowel Movement A Week

Have been experiencing slight bleeding with bowel movement a week before my period is due, then continued light brown spotting until period occurs (5-7 days). I have had both an abdominal and transvaginal ultrasound, and a pap smear and HPV testing and everything has come back normal. This has been happening for 18 months, for as long as i have been off the contracetive pill.