When do you normally start ovulation testing?

Jessica • PCOS - 👼🏻(Miscarriage Apr2018) Expecting Identical Twins 👶🏻👶🏻 April 27th, 2019

I have PCOS and normal have about 40-50 day cycles. I’m on Metformin and last month only had a 30 day cycle. I’m hoping this is the Metformin working. But I’m wondering when I should start ovulation testing for 30 day cycles.