What is Ovulation?
Ovulation is when your body releases a mature egg from the ovary. This usually happens around the middle of your menstrual cycle, typically 14 days before your next period starts. If you have a 28-day cycle, ovulation often happens around day 14.
When Are You Most Fertile?
-
An egg can only be fertilized for 12–24 hours after ovulation.
-
Sperm, however, can live inside the body for up to 5 days.
That means your most fertile days are the 5 days before ovulation and the day of ovulation itself—usually around day 10 to 18 of your cycle.
If the egg is fertilized, it may implant in the uterus 6–12 days later. If not, your period will start, and the cycle begins again.
How Can You Predict Ovulation?
1. Track Your Menstrual Cycle
If your cycles are regular, this is a simple and effective method. Just track the first day of your period each month. Ovulation typically happens 14 days before your next period.
⚠️ If your cycle is irregular, this method may not be accurate.
2. Monitor Your Basal Body Temperature (BBT)
Use a special thermometer to take your temperature first thing in the morning, before getting out of bed.
Your BBT usually dips slightly just before ovulation and rises about 0.5°F (0.3°C) right after.
Tracking this over a few months can help you find a pattern—but illness, poor sleep, or stress can affect the results.
3. Use an Ovulation Test Kit (OPK)
These at-home tests detect a surge in Luteinizing Hormone (LH), which happens 24–48 hours before ovulation.
They’re easy to use and around 99% accurate at detecting the hormone.
Some newer kits also track estrogen or salt levels in saliva or sweat, which may rise earlier than LH. These require more tracking but can predict ovulation sooner.
Quick Summary
-
Ovulation usually happens about 14 days before your next period.
-
Your best chance of getting pregnant is during the 5 days leading up to ovulation and on ovulation day.
-
You can predict ovulation by tracking your cycle, monitoring your temperature, or using ovulation kits.