Ovulation and OPKs-which day are you really ovulating?

According to the OPK instructions, I need to BD on the day I detect LH surge and the next day, 24-36 hours after detecting the surge. Surge day pre-ovulation, 2nd day should ovulate. I noticed my LH surge on afternoon of day 13. Negative at the same time on day 12, so I believe I should have ovulated day 14. First BD within 24 hours of detection (15 hours actually) morning of day 14. But can it take less than 24 hours for the surge to happen between testings? If so, it could have first surged day 12 so I may have ovulated day 13. Someone with experience using OPK along with BBT and CM may have some insight? Hoping I'm pregnant but somewhat doubtful.

generally speaking you will o approx 24-36 hours after LH surge (pos opk). so if you surge on day 13 then you should o on the 14th. according to my md, he says not to bd on the day of surge but the following 2. and remember sperm can live for up to 72 hours...good luck and God Bless!!

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