petal the ivf drugs are more likely to make it show on scans and you have what sounds like pco rather than pcos so it is likely that you may have just aquired it or that it has been laying dormant and not been picked up.. If you had full blown pcos you'd have all the symptoms.
Lots of people have pco and then it goes, then it come back etc.. it's all linked to your health, diet and sugar intake.
Ju x