What Causes A Milky Discharge In The Vagina?

I have a milky like discharge down there?
I just went to the doctor 6 weeks ago and i had a pap smear/std check the results for the std come out normal but pap smear come out abnormal. But now i have a milky like discharge it kinda smells like yeast not fishy or anything like that and sometimes its kinda heavy where my pants are actually wet...I don't know what to do should i go back to the doctor??? help