How does femSense know when I am fertile?

femSense reliably detects your ovulation and most fertile days using continuous temperature measurement and the well-known temperature method.
Based on your previous periods the femSense app can predict your fertile window, the days you are most likely to get pregnant. The femSense sensor patch measures your body temperature continuously, 24/7 during your fertile window to measure and confirm your ovulation. You are fertile in the days shortly before and immediately after ovulation.