Help!! Ovulation issue

Alex
When will I/did I ovulate??Okay so I have pcos I take 1000mg metformin daily. This month I got my AF on my own and Doctor started my on Letrozole(Femara) 2.5 mg cycle days 3-7. I'm on cycle day 13 now. Ovulation tests aren't always reliable with pcos so we have had sex everyday for the past 4 days incase I ovulated. I'm just not sure which day would be most likely for me to have ovulated if I did already. Thanks in advance for any input!