Thanks for your query at DocotorSpring
Women with PCOS have erratic periods, and hence, extremely erratic ovulation.
There is no proper way to know when you would have ovulated.
Also, the emergency contraceptive ( morning after pill ) prevents pregnancy when taken within 24 hours, in more than 95 % of cases.
All said and done, the odds of pregnancy in your case are extremely low ( less than 5 % ) considering that you have taken the pill timely.
Adding to that the infrequent ovulation associated with PCOS, I would put your likelihood of getting pregnant at even lower than that (near Zero).
Do not stress out !