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The Fertile Window Explained: When You Can Actually Get

The fertile window is the 5–6 days each cycle when pregnancy is possible — 5 days before ovulation plus ovulation day. Day 14 is a myth for most people. Here's

The fertile window is narrower than most people assume, and its timing is less predictable than period apps suggest. The common advice to "try on Day 14" is based on a population average that's wrong for most individual cycles — sometimes off by a week or more. The Biology of the Fertile Window Two biological facts define the fertile window: 1. Egg viability: After ovulation, the egg survives for 12–24 hours. If no sperm reaches it within that window, the cycle ends without fertilization. 2. Sperm viability: In fertile cervical mucus (the thin, slippery, egg white consistency produced under high estrogen), sperm can survive for up to 5 days. In the absence of this mucus — or in the hostile, thick mucus that dominates the rest of the cycle — sperm die within hours. These two facts together define the fertile window: the 5 days before ovulation (when sperm deposited in fertile mucus can survive to meet the egg when it's released) plus ovulation day itself (the last day the egg is viable). That's 6 days total. Most pregnancies result from intercourse 1–2 days before ovulation — when sperm are already in the fallopian tube, waiting. Why "Day 14" Is Wrong for Most People The Day 14 assu