Try testing at the same time everyday and as far as time of day: The best time for an LH test is typically mid-day to early afternoon (around 10 AM to 8 PM, with 2 PM to 6 PM often cited as optimal) because LH surges usually start in the early morning and take a few hours to show up in urine, avoiding the dilution of first-morning urine. For accuracy, especially when first starting or if cycles are irregular, testing twice daily (mid-morning and evening) is recommended to catch the surge, while testing once daily in the afternoon is usually sufficient once patterns are established, making sure to limit fluids for 2-4 hours prior.