What Causes Irregular Periods, Spotting And White Vaginal Discharge?

hi i have a question i had my period in july it ended on the 6th it was a little wacked out and then went 9 days with nothing then had spotting now it is aug. 31 and still no period it has been 56 days since the end of my last period and i have had 2 neg. urin pregnacy test...what do you think it could be i went to the doctors in july and they did a urin test but came up neg and then they didnt do anything else i thought they would have at least done an ultra sound to make sure...along with this i have had a white milky discharge and a lot of it? please help

thank you