Posting this for a friend. Back story: Husband had a vasectomy, he went in for the first shooters test but not the 2nd. She tested because (her periods are irregular) she had dark brown spotting on Friday and used a tampon, after 8 hours there was barely anything on it and nothing since. We all know blue dyes suck but it's what she had.. she will test again in the morning with the other blue dye she had then if that is inconclusive will buy a FRER. What are the chances this is a true positive?