Ovulation usually takes place 12–16 days before the start of your next period. For a woman with a 28-day menstrual cycle (the first day of menstruation being day one), ovulation takes place sometime around day 13 to 15. The length of a normal menstrual cycle, however, varies between 23 days and 35 days so ovulation could occur earlier or later in your cycle.

The simplest way to determine your most fertile time is to pay attention to your body and learn to spot the signs that ovulation is imminent.

Changes in cervical mucus.
Several studies have found that monitoring changes in the cervical mucus is an accurate and useful method for women to use to predict their most fertile days. As your cycle progresses, your cervical mucus increases in volume and changes texture. The greater volume and changes in texture reflect your body's rising levels of the hormone oestrogen and show that you are close to ovulating. You are considered most fertile when the mucus becomes clear, slippery and stretchy. The role of this mucus is to nourish, protect and speed the sperm on its way up through the uterus and into the fallopian tubes for the rendezvous with your egg. Many women compare the copious, watery mucus at this stage to raw egg whites.

Lower abdominal pain.
About one-fifth of women actually feel ovulatory activity, which can range from mild achiness to twinges of pain. Some women describe it as "one-sided back ache" or a specific tenderness. The condition, called mittelschmerz,may last anywhere from a few minutes to a few hours. If you notice the same type of pain at roughly the same time each month, check the condition of your cervical mucus as well. Ovulatory pain can be a useful guide to their fertile window for some women.

You may not be aware of it but you may be showing other signs that you are at your most fertile. Studies of changes in appearance and behaviour across the menstrual cycle have become more popular in recent years. Think back over your menstrual cycle and you may find that some of the following peaked when you were approaching ovulation:

Feeling sexy and flirty.
Increased libido, improved mood and feeling more sociable may all be signs that you're at your most fertile. If you are in a stable partnership, you may notice a peak in sexual desire when you are in the ovulatory phase of your menstrual cycle. Whether in a settled relationship or not, the fertile window is the period when women are more likely to feel like going out, preferably where they can socialise with other men and be a little flirtatious. If you're in a relationship, you may also have noticed that your partner gets a little more possessive and attentive at this time!

Looking hot, hot, hot!
Studies have found that both how you feel and how you look on the attractiveness stakes goes up when you near ovulation. A recent study found that women reported feeling more physically attractive at this fertile time. You may look more attractive to others too, as it has been found that women take more care with their appearance when they are at their most fertile. Without realising it, you may choose clothes that flatter you and take more care over grooming and accessorising; and the closer to ovulation the hotter women look. Although we may think that we don't use sexual displays, as commonly seen in the animal world, we can still use our feminine wiles to make sure we catch the eye of the prime male in our life.

With a scent to drive a man wild.
Not only may you look good, you may also smell hot, hot, hot! It has been found that women smell more attractive to men when they are in the ovulatory phase of their cycle than when this fertile window has passed. You may think that nobody knows you're ovulating but those tell-tale pheromones give the game away.

How to increase your chances of conception

If you have unprotected sex every two to three days then sperm with good motility will be in the right place whenever you ovulate. Regular sex throughout your cycle is the approach that fertility experts recommend for increasing your chances of getting pregnant. Making love when your cervical mucus is wet, slippery and therefore most receptive to sperm will also increase your chances of conception. And you'll be happy to know that the odds are with you.

In normally fertile couples, there is a 20 to 30 per cent chance of getting pregnant each cycle. This means around 84 per cent of women who have regular sex without using birth control will get pregnant within one year. If they keep on trying, half of the remainder will get pregnant in the following year, giving a grand total of 92 per cent of couples conceiving within two years.