Spotting since CD 31 (on day 35 now)

Could this be AF?  It is only brown in color and comes and goes.  No cramping and I always have that with AF since I have endo.  I took a pregancy test and saw the faintest of line if at all as you had to hold it just right to see it so I think it was actually nothing.  I am going to accupuncture today to try to regulate my cycle, etc.  I just can't help thinking what if I really am pg...I had symptoms a week ago and they just stopped suddenly so perhaps I am having an early m/c?  Sigh...this is so frustrating.  I didn't chart as I was trying to be more "natural" about TTC but I am definitely charting again...I would have known what is going on right now!  Vent over.