Opk. Help! I'm so confused

Kenzie • 3 wonderful boys. Trying to get our 4 th baby!!! Maybe a girl ???
Ok so does it matter what time to take opk test ? Do you need to hold pee for a while ? And is first morning pee more accurate.. It's so weird I will get one that almost positive then 1 hr later. No. Second line at all. I'm on cycle day 12  I should ovulate on day 14