Determination of ovulation in a cycle.

Hello. I visited a gynae for pre pregnancy consulation in August. As i had history of PCOS which is currently under control, he asked me to measure progesterone on day 22 of cycle. When i got it measured in September, value was 10.9 nm/ml. He said that I have not ovulated that cycle as value is low. But I had menstrual bleeding after day 31. Next cycle (october) I used LH kit to detect fertile days and it came positive from day 15. Previously, in May, I had done follicular study and ovulation was detected on day 18. but that cycle was of 34 days. My cycle varies from 31 to 34 days. So my question is what is expected value of progesterone to detect ovulation? also, if my cycle is longer than a typical one, shall i test for progesterone on 23 or 24 day? kindly help me to understand.