Free Ovulation Calculator : What Is An Ovulation Calendar?

If you want to conceive naturally, you need to have intercourse at the right time of the month to get pregnant. BellyBelly’s ovulation calculator can help you determine your fertile days to boost your chances of getting pregnant.

Try our ovulation calendar to discover when you’re most likely to ovulate and be in the fertile stage of your menstrual cycle.

Your fertility ‘window’ is open for about six days. Being able to pinpoint this phase in your menstrual cycle allows you to time sex effectively to maximise your chances to get pregnant.

What is an ovulation calculator?

An ovulation calculator is a simple ovulation predictor tool that estimates your fertility window and helps you find the optimal time to achieve pregnancy.

Are ovulation calculators accurate?

Ovulation calculators provide a guide to the estimated time that ovulation is likely to occur. They rely on the accuracy of the information you provide. For women with regular cycles, the more accurate the information, the better the results will be. If you have an irregular cycle with varying cycle lengths, the ovulation calculator is unlikely to be precise, but will at least offer you a guide to fertile dates.

How to use the ovulation calendar

BellyBelly’s user friendly ovulation calendar will take the stress out of determining your pregnancy dates. For accurate results, you need to know:

1. The date of the first day of your last period (LMP)
2. Your average cycle length.

Once you enter the information into the ovulation calendar, it will crunch the numbers and present your results.

It should provide you with a date guide, to improve your chances of getting pregnant. The ovulation calendar will highlight your predicted fertile days. Even better, it will show you information for the next three months, allowing you to schedule date nights in advance.

What if I don’t know the first day of my last menstrual period?

Unfortunately, the ovulation calculator won’t work if you can’t enter the first day of your last period. This piece of information is crucial for the calculations that will help you achieve a pregnancy. Be sure to note down the day when your next period starts, then you can use the calendar next month to determine your day of ovulation.

I have irregular periods. Will the ovulation calendar still work?

The average menstrual cycle is around 28 days long; however, many women have cycles that are longer or shorter than that. As long as your menstrual cycle has the same number of days each month – whether that’s 26 days or 31 days – the calculator should work.

If your cycle length varies each month, the calculator won’t be able to make accurate predictions about your next ovulation date or your most fertile days. If you are planning a healthy pregnancy, then charting your last period will help the calculator work out your fertile window and when you will probably ovulate.

What is ovulation?

During ovulation, the ovaries release a mature egg, which makes its way down the Fallopian tube to the uterus. If conception doesn’t occur, the woman’s body eventually reabsorbs the egg, and she will have a period.

For conception and pregnancy to occur, sperm must fertilise the egg soon after its release from the ovary. The egg will only survive for between 12 and 24 hours after you ovulate, so you must have intercourse at the right time.

The good news is that sperm can survive inside the body for up to five days before you ovulate, so it’s there when you need it. The fertile window begins five days before and ends the day after ovulation.

When does ovulation occur?

The timing of ovulation varies among women; however, it typically occurs around 14 days before your period. Menstrual cycles vary in length between individuals and from month to month. The best way to accurately predict when you will ovulate is to familiarise yourself with your menstrual cycle and, in the days before ovulation, monitor the potential signs of ovulation, such as changes in cervical mucus.

What are other fertility indicators?

If you’re trying for a baby, you probably want to maximise your chances of pregnancy every month. Using the ovulation calculator estimates, you can predict your most fertile days. There are also other signs to look out for, to make sure you don’t miss your fertile window. Here are some examples:

Cervical mucus

When using the bathroom, you might have noticed vaginal discharge in your underwear or on the toilet paper. Perhaps you didn’t pay much attention to the consistency or the appearance of this discharge but it could hold the secret to identifying your fertile day. Vaginal mucus changes throughout the menstrual cycle in response to hormonal changes taking place within your body.

Cervical mucus can be thick or tacky when you’re not fertile but you will notice a significant change when you’re ovulating and it’s your fertile time.

Try keeping a daily log, where you note changes in your mucus. It can help you predict when ovulation will occur, more accurately identify the best times to conceive and increase your chances of pregnancy.

What does ovulation discharge look like?

Around the time of ovulation, your vaginal discharge will take on the consistency of raw egg white. It will be clear and slippery, and will stretch if you hold it between your thumb and forefinger. The discharge is slippery so it can facilitate the rapid movement of the sperm to the egg.

Basal body temperature (BBT)

You can also track your basal body temperature for a detailed insight into your menstrual cycle. Your basal body temperature is the temperature your body maintains when you’re at rest. Basal body temperature increases in the days following ovulation.

Although it might not sound helpful to track temperatures when ovulation has already occurred, doing so can help you predict more accurately when ovulation is likely to happen in the future. A combination of tracking your basal body temperature and observing changes in your cervical mucus can help you develop a better understanding of your body.

Luteinizing hormone (LH)

LH plays a crucial role in the menstrual cycle – particularly in triggering ovulation. There is a sharp rise in LH about 24-36 hours before ovulation occurs. Tracking your LH levels with an ovulation test can help you identify this rise in the days leading to ovulation, letting you know when ovulation is likely to occur. It’s worth bearing in mind that the cost of using an ovulation test daily can soon add up; tracking cervical mucus is a more cost effective way to predict your ovulation date.

An ovulation calculator on its own is not the most reliable method of identifying your unique pattern of ovulation and fertile phase. A 2018 study published in Current Medical Research and Opinion found that an ovulation calendar alone was an inaccurate method for predicting the ovulation date. For this reason, we recommend also tracking your cervical mucus to get a clearer understanding of your ovulation cycle.

Keeping in mind the potential inaccuracies of predicting your fertile days, it’s worth having regular unprotected sex throughout the month, to maximise your chances of conceiving. Even if you have misjudged when ovulation will occur, you might still get pregnant during your fertile window.

When should I take a pregnancy test based on ovulation?

Although pregnancy test manufacturers might think otherwise, the best time to take a pregnancy test is on the first day you’ve missed a period. Wait until the day your next period is due, then you can take a pregnancy test to see if you’re pregnant. Follow the manufacturer’s instructions and read the results within the correct timeframe.