Opk positive for 4 days?

hi i am confused i took an opk on day 12 and it looked positive i also had a lot of ewcm. i had bd that day but then i took another opk just to be curious the next day and the test line was even darker. according to the ovulation calender i was supposed to O on day 14. what r my chances and what does so many p opk mean i have 4 p opks