OPK and ovualtion help please

Hi ladies just wondering about opk testing I am always 28 day cycle and always O on cycle day 14 with always pos opk on day 12, this month I started testing day 11 finally got a pos opk on day 15 I always O 2days after getting a pos which would put that today cycle day 17.. We BD days8,9,10,13,14,15,16,17 do you think for insurance purposes we should BD again tomorrow? Or wait a day then one more time? This is the first month that we have been successful in BD on O day (well what I think is O day) any help would be appreciated