Last month my period lasted 6 days. My period usually only last at most 4 days and usually comes on the 27th to 29th cycle day. I am on birth control. This month I was 3 days late. I have been feeling nauseas and am very moody. When my period finally started it was brown with small clots. It was mostly only when I wiped. It only lasted around 4 hrs and its pretty much gone again. I have been having bad cramps since it started and they almost feel like they are coming from my kidneys. I have been having bad ingestion and back pains for the last few weeks. I took a pregnancy test thinking maybe that was it when I was two days late but it was negative. What could be causing this?