What Causes Brownish Vaginal Discharge?

I was 4 days late for my period. I took a hpt the first day I was late and that was clearly negative. I took another one on the 4th day late and I thought I saw a faint second line....but I was being rushed and placed the test in the drawer. My period was extremely short and nowhere near as heavy as it normally is. I noticed 2 days ago that I was spotting brownish discharge only when I used the bathroom. Yesterday, when I used the bathroom it looked like there was a small spot of fresh blood when I wiped. I can normally tell when I ovulate because I get pain on either side by my ovary. However, for the last 3 days I have had mild period like cramps in the center....not to either side. Im not sure if this is normal or not.