Your close your lookin for both lines the same color or test line darker then control line whatever comes first is your positive. Ovulation can occur in 12-48 hours after. Opks don’t confirm ovulation or dpo so if you want more accuracy add bbt to confirm ovulation to know when you ovulated, dpo, luteal phase length (is from the day after ovulation to period which stays the same each cycle give or take 1-2 days. Average length is 12-14 days give or take 1-2 days.) when period is coming by temp drop or if you miss your period and your temp stays up then there is a chance for pregnancy