Fertile window
Your fertile window is a ~6-day span each cycle when pregnancy is possible: the five days leading up to ovulation plus ovulation day itself. Sperm can live up to five days; the egg lives about 24 hours.
Estimating ovulation
Ovulation usually happens ~14 days before your next period. In a 28-day cycle that's day 14; in a 30-day cycle it's day 16. We calculate it from your cycle length, not a fixed date.
Signs to watch for
Egg-white cervical mucus, a slight rise in basal body temperature after ovulation, mild one-sided pelvic twinge (mittelschmerz), and increased libido are common ovulation cues.
Whether you're trying or avoiding
The fertile window works both ways. Log symptoms and flow consistently so the highlighted days on your dashboard reflect your actual cycle, not an average.