Premom Ovulation Calculator helps users estimate an ovulation day, fertile window, next period, and when to begin LH ovulation test strips from the first day of the last period and average cycle length. It opens an interactive educational calculator in ChatGPT and supports English, German, and Simplified Chinese. The app does not connect to a Premom account, sell products, or direct users to an external website. Results are cycle-based educational estimates and are not a substitute for professional medical advice.