What Causes Irregular Periods, Smelly Vagina And Pain During Sex With No Infection?

hi im 18 years old and i went to my gp with alot of discharge with a strogn smell from my vagina and irregular periods and bad tummy during intercourse. my gp did swabs which came back normal and she said she was very suprised as she thought some sort of infection would show up. she reffered me to a gum clinic and just got results sayign that they found pus cells but dont know what infection my bodies fighting. what could this be im very worried?