The best time for conception

Apart from being healthy, what might help you get pregnant? Sex! (Or intercourse at the right time, to be technical about it.)

The best time to try and conceive is during the ‘fertile window’ of the menstrual cycle; this is different for different women.

The fertile window

We’re talking about the days in a woman’s menstrual cycle when pregnancy is possible. Pregnancy is technically possible during the six days before ovulation and the day of ovulation. The likelihood of actually becoming pregnant, though, is dramatically increased if you have intercourse in the three days leading up to and including ovulation.

What is ovulation?

Ovulation is when a mature egg is released from the ovary, moves down the fallopian tube, and is available in the fallopian tube to be fertilised.

How do you know you’re ovulating?

These are the most accurate signs that ovulation is about to occur:

  • Mucus changes – around the time of ovulation you may notice your vagina’s mucus is clear, slick and slippery, the consistency of egg white. This is the best sign that ovulation is getting close.
  • Use an ovulation predictor kit and ovulation calculator.

You can start testing with your ovulation predictor kit a few days before your estimated day of ovulation. Subtract 17 days from your average cycle length and start testing from this day of your cycle, e.g. if you have a 28 day cycle, you would start testing from day 11. A positive result means you are going to ovulate within the next 24 to 36 hours.

This will tell you that ovulation has occurred:

  • Record your basal body temperature (BBT)

Women can determine their ovulation day by taking their basal body temperature (BBT) every day throughout their cycle. The BBT is taken using a BBT thermometer just after waking up in the morning, while still resting (before speaking or getting up). The BBT rises about half a degree Celsius after ovulation has occurred.  So the BBT is useful if you want to know that you do ovulate and when in a cycle it is occurring.

Tracking your ovulation

  • Work out the length of your average menstrual cycle. Day one is the first day of the menstrual period and the last day is the day before the next period begins.
  • Ovulation happens about two weeks before the next expected period. So if your average menstrual cycle is 28 days, you ovulate around day 14.
  • However women’s cycles can vary, so to know that you are ovulating and on which day of your cycle you are ovulating, observe your fertility signs – cervical mucus and basal body temperature – throughout your cycle and record them on a chart.
  • Remember the three day ‘fertile window’ leading up to and including ovulation? If you have a 28 day cycle, with ovulation typically happening on day 14, the ‘fertile window’ starts on day 12. If you have longer cycles, say 35 days between periods and ovulation happens on day 21, the ‘fertile window’ starts on day 19. If you have very short cycles, say 21 days and ovulation happens on day 7, your ‘fertile window’ would start on day 5.

Myth conception

The myth:

"The best time to try to conceive is day 14 of your menstrual cycle. "

The truth:

The only time a woman can conceive is during the ‘fertile window’ of the menstrual cycle.

The best time to try to conceive depends on how long the woman’s menstrual cycles are. The ’fertile window’ in the menstrual cycle is the two to three days leading up to ovulation, when the egg is released from the ovary. For women with 28 day menstrual cycles - with day one the first day of the menstrual period - the best time to try to conceive is day 12-14. For women with shorter cycles of 21 days, the best time to try is day 5-7. Women with 35 days between periods should focus their efforts to get pregnant between day 19 and 21.

Fertility Factors: timing

When you're trying to get pregnant, timing is everything, as Justine and Mick are well aware.

Ovulation calculator

Please select the first day of your last menstrual period:

Usual number of days in your cycle:

Other factors affecting women's fertilityMen and fertility