window.onload = function() {
var today = new Date();
var dd = String(today.getDate()).padStart(2, '0');
var mm = String(today.getMonth() + 1).padStart(2, '0'); //January is 0!
var yyyy = today.getFullYear();
var formattedToday = yyyy + '-' + mm + '-' + dd;
document.getElementById('checkDate').value = formattedToday;
};
function calculateMenstrualStatus() {
var lmpDateStr = document.getElementById('lmpDate').value;
var averageCycleLengthStr = document.getElementById('averageCycleLength').value;
var checkDateStr = document.getElementById('checkDate').value;
var resultDiv = document.getElementById('result');
if (!lmpDateStr || !averageCycleLengthStr || !checkDateStr) {
resultDiv.innerHTML = "Please fill in all fields.";
return;
}
var lmpDate = new Date(lmpDateStr);
var averageCycleLength = parseInt(averageCycleLengthStr);
var checkDate = new Date(checkDateStr);
// Reset time components to avoid issues with timezones/daylight saving
lmpDate.setHours(0, 0, 0, 0);
checkDate.setHours(0, 0, 0, 0);
if (isNaN(lmpDate.getTime()) || isNaN(checkDate.getTime())) {
resultDiv.innerHTML = "Please enter valid dates.";
return;
}
if (isNaN(averageCycleLength) || averageCycleLength 0) {
resultDiv.innerHTML = "Your period is approximately " + daysDiff + " days late.";
} else if (daysDiff === 0) {
resultDiv.innerHTML = "Your period is expected today.";
} else {
resultDiv.innerHTML = "Your period is expected in approximately " + Math.abs(daysDiff) + " days.";
}
}
Understanding Your Menstrual Cycle
The menstrual cycle is a natural process that women experience, typically lasting between 21 to 35 days, with an average of 28 days. It begins on the first day of your period and ends the day before your next period starts. Understanding your cycle is key to knowing when your period is due and identifying if it's late.
How to Use the Am I Late Menstrual Calculator
Last Menstrual Period (LMP) Start Date: Enter the first day of your last period. This is crucial for establishing the starting point of your current cycle.
Average Cycle Length (days): Input the typical number of days your menstrual cycle lasts. If you're unsure, 28 days is a common average, but tracking for a few months can give you a more accurate personal average.
Date to Check: This field defaults to today's date, but you can change it to any date you wish to check your menstrual status for.
Click "Calculate" to see if your period is late, on time, or still expected.
What Does "Late" Mean?
A period is generally considered "late" if it hasn't arrived within a few days of its expected start date. While the calculator provides a numerical difference, it's important to remember that cycle lengths can vary slightly from month to month, even for those with regular cycles. Stress, diet, exercise, travel, illness, and hormonal changes can all influence your cycle.
Common Reasons for a Late Period (Other Than Pregnancy)
Stress: High levels of stress can disrupt the hormones that regulate your cycle.
Weight Changes: Significant weight gain or loss can affect your hormonal balance.
Excessive Exercise: Intense physical activity can sometimes lead to missed or irregular periods.
Diet: Nutritional deficiencies or extreme dieting can impact your cycle.
Travel: Changes in routine and time zones can temporarily throw off your cycle.
Illness: Acute or chronic illnesses can delay your period.
Medications: Certain medications, including some contraceptives, can affect cycle regularity.
Hormonal Imbalances: Conditions like Polycystic Ovary Syndrome (PCOS) or thyroid disorders can cause irregular periods.
Perimenopause: As women approach menopause, cycles often become irregular.
When to Consult a Doctor
While occasional late periods are often normal, it's advisable to consult a healthcare professional if:
Your period is consistently late or missed.
You suspect you might be pregnant.
You experience unusual symptoms along with a late period (e.g., severe pain, heavy bleeding, fever).
Your cycle length suddenly changes significantly without an obvious reason.
You have gone more than 90 days without a period.
This calculator is a helpful tool for tracking and understanding your cycle, but it should not replace professional medical advice. Always consult with a doctor for personalized guidance regarding your health.