OPK First Time

(I posted this to the TTC with PCOS board but figured it wouldnt hurt to post here too since this is the main board for me)

I have been diagnosed with PCOS, and most places I've read have stated that OPKs aren't really helpful for people with PCOS. But I've been trying for almost a year after a miscarriage. Had 2 rounds of IUI with no success. I've been on Metformin. Dr. prescribed Clomid in the past. Had both it and Femara during my IUI rounds. And here I am...with no baby. So I figure trying an opk wouldnt hurt.

I ordered a not too expensive kit from Amazon (figured why spend a lot on something that may be useless to me) but dont know when to start. It has a total of 50 tests. I am on day 3 of cycle, and my cycles are irregular. Should I just start peeing on sticks once menstruation stops? How many times a day, and at what time of the day should I test? I read first morning isn't the best for OPKs. Thanks for your help!