Although Ovia doesn't need ovulation test results to project your fertile window, confirming a positive ovulation prediction will help solidify your projections. Ovulation occurs when an ovary releases an egg to be fertilized. This is triggered by a rise in the hormone LH about 24-36 hours before ovulation, and most ovulation tests or Ovulation Predictor Kits (OPKs) detect this surge in LH through a woman's urine. Tracking your ovulation tests from cycle to cycle can help you determine any consistency in your relative ovulation day across multiple cycles, and can also help you confirm that ovulation has or has not already occurred within a cycle. Read more here.