When do i ovulate?please help confused?

Question

last AF was 8/11 my cycle is usually 24 days but june i was 3 days late and august i was 11 days august was a 39cycle had BFN on HPT when would i ovulate? ovulation calculator says tomorrow 8/23.OPK negative. chart says i've been fertile 5 days after AF was done. i'm so confused