Luteinizing Hormone (LH) is always present in your urine and increases just before ovulation. This increase, or “surge” in LH, triggers ovulation, which is the release of an egg from your ovaries and the most fertile time of your cycle. The FIRST RESPONSE™ Ovulation Test Kit detects the LH surge, which precedes ovulation by 24-36 hours. Your two most fertile days begin with the LH surge. If you have intercourse within the next 24-36 hours of your surge, you will maximize your chances of becoming pregnant.

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