Hi, my period was due on February 4th, 26 days from the last. I see brown blood only when I wipe, yesterday & today. My last period was January 10-12th and those three days I only saw red blood when I would wipe. My period before that was December 16th-18th and was light but definately present. The last time I had intercourse was December 11th. I took three pregnancy tests , the most recent about two weeks ago, and all came back negative. What could possibly be happening?