Health Blogger Widget: Fertility Window Tracker Fertility Window Tracker First day of last period: Average cycle length (days): 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 Luteal phase length (days): 10 11 12 13 14 15 16 Calculate Fertility Window Your Fertility Window Note: This is an estimate. For medical advice, consult your healthcare provider. Powered by HealthTopicsHub.com