What Causes Delay In Periods,brown Spotting And Bright Yellow Urination?

Hi I'm 3 days late for my period my nipples are sensitive I have had no appetite for the last 2 weeks besides a few cravings I'm always tired and my moods are like a roller coaster I had light brown spotting for 2 days that was only noticeable when I wiped myself an my urine is a bright yellow I have done a HDt that was negative but am awaiting bloods what can this be?