As soon as the LH surge is detected, successful fertilization is most likely to take place one to three days afterwards, with peak fertility at about 36 hours past the LH surge. Have intercourse during the 2-3 days following your LH surge to maximize your chances of getting pregnant during that cycle.
LH should be measured on a daily basis and unlike pregnancy tests, morning is not the best time to collect samples for ovulation tests (unless you are testing saliva). LH is synthesized in your body early in the morning and will not appear in your urine until the afternoon- which is the best time for testing. Be sure to test at the same time every day and also refrain from drinking liquids about 2 hours prior to testing, because otherwise your sample will be diluted and may interfere with accurate detection of LH.
When used correctly, ovulation tests are excellent predictors of ovulation and are very helpful when trying to become pregnant. It is best to use a combination of methods when trying to pinpoint ovulation. Ovulation tests can be one of your methods, along with tracking your BBT, observing changes in your cervical mucus, monitoring your physical and emotional symptoms and checking the position and shape of your cervix. Ovulation testing can be very accurate, as long as the directions are followed exactly.