An Ovulation Predictor Kit (OPK) is a tool used to help individuals identify their fertile window by detecting the surge of the hormone luteinizing hormone (LH) in urine. This surge typically occurs 24 to 36 hours before ovulation, making it easier to time intercourse for conception. OPKs come in various forms, including test strips and digital devices, and are widely available at pharmacies. Using an OPK involves collecting urine samples and following the kit's instructions to interpret the results. A positive result indicates that ovulation is likely to occur soon, which can be beneficial for those trying to conceive. Regular use can help track menstrual cycles and improve understanding of reproductive health.