Fertility Window Calculator - Track Your Ovulation & Best Conception Days
🌸
Enter your cycle details to see your fertility window
Get personalized ovulation predictions and conception probability
Ovulation Day
Highest chance of conception
Each bar shows conception probability for that day
Understanding Your Fertility
🥚
Ovulation Timing
Eggs survive 12-24 hours after release. The 5 days before ovulation plus ovulation day create your fertile window.
🐛
Sperm Survival
Healthy sperm can survive up to 5 days in the female reproductive tract, waiting for the egg.
📈
Conception Odds
Conception probability increases from 10% five days before ovulation to 33% on ovulation day.
⏰
Cycle Variations
Only 10% of women have a perfect 28-day cycle. Track for 3 months for best accuracy.
🌡️
Signs of Ovulation
Cervical mucus becomes clear/stretchy, basal body temperature rises 0.5°F, and LH surges.
💡
Maximizing Chances
Have intercourse every 1-2 days during your fertile window, especially the 2 days before ovulation.
Share Your Fertility Results
Share with your partner or save for later
`;
const printWindow = window.open('', '_blank');
printWindow.document.write(printContent);
printWindow.document.close();
printWindow.focus();
setTimeout(() => printWindow.print(), 500);
}
// Display success message with animation
function showSuccessMessage(message) {
const messageDiv = document.createElement('div');
messageDiv.style.cssText = `
position: fixed;
top: 30px;
right: 30px;
background: linear-gradient(135deg, #4CAF50, #66bb6a);
color: white;
padding: 20px 25px;
border-radius: 12px;
box-shadow: 0 8px 24px rgba(76, 175, 80, 0.3);
z-index: 3000;
font-weight: 600;
animation: slideInRight 0.5s ease;
`;
messageDiv.textContent = message;
document.body.appendChild(messageDiv);
setTimeout(() => {
messageDiv.style.animation = 'fadeOut 0.5s ease';
setTimeout(() => messageDiv.remove(), 500);
}, 3000);
}
// Helper functions
function showElement(id) {
document.getElementById(id).style.display = 'block';
}
function hideElement(id) {
document.getElementById(id).style.display = 'none';
}
function showError(id, message) {
const errorElement = document.getElementById(id);
errorElement.textContent = message;
errorElement.style.display = 'block';
}
function hideError(id) {
document.getElementById(id).style.display = 'none';
}
// Add fadeOut animation
const style = document.createElement('style');
style.textContent = `
@keyframes fadeOut {
from { opacity: 1; transform: translateX(0); }
to { opacity: 0; transform: translateX(20px); }
}
`;
document.head.appendChild(style);
// Auto-save to localStorage
function autoSave() {
if (currentCycleData) {
localStorage.setItem('fertilityCalculatorData', JSON.stringify({
...currentCycleData,
lmpDate: currentCycleData.lmpDate.toISOString(),
ovulationDate: currentCycleData.ovulationDate.toISOString(),
fertileStart: currentCycleData.fertileStart.toISOString(),
fertileEnd: currentCycleData.fertileEnd.toISOString(),
nextPeriod: currentCycleData.nextPeriod.toISOString(),
fertileWindow: currentCycleData.fertileWindow.map(d => ({
...d,
date: d.date.toISOString()
}))
}));
}
}
// Load saved data on page load
window.addEventListener('load', () => {
const savedData = localStorage.getItem('fertilityCalculatorData');
if (savedData) {
try {
const data = JSON.parse(savedData);
// Check if data is still valid
const savedDate = new Date(data.lmpDate);
const daysSince = Math.floor((new Date() - savedDate) / (1000 * 60 * 60 * 24));
if (daysSince <= data.cycleLength + 7) { // Valid if within one cycle + 7 days
document.getElementById('lmpDate').value = savedDate.toISOString().split('T')[0];
document.getElementById('cycleLength').value = data.cycleLength;
document.getElementById('lutealPhase').value = data.lutealPhase;
document.getElementById('calcMethod').value = data.calculationMethod;
// Auto-calculate
setTimeout(() => calculateFertility(), 500);
}
} catch (e) {
console.log('Failed to load saved data:', e);
}
}
});
// Save data after calculation
document.querySelector('.btn-primary').addEventListener('click', () => {
setTimeout(() => autoSave(), 2000);
});
// Google Analytics tracking
function gtag() {
// Placeholder for Google Analytics
if (window.gtag) {
window.gtag.apply(window, arguments);
}
}
Share Your Fertility Results
Share with your partner or save for later