How to get pregnant

Many of us learned a little bit about the theory of human reproduction as part of our school curriculum. It is worth refreshing our understanding of how babies are conceived, both from the female and male perspective, so that we have greater insight into the fertility testing and treatment process – if needed. Here is a practical overview of how you get pregnant.


Conception starts at the moment of fertilisation, when the sperm penetrates the outer shell of the egg, and an embryo is formed. This process usually happens in a fallopian tube.

Over the next four to six days the embryo moves down the fallopian tube to the uterus, where it implants in the womb lining and hopefully continues to grow. Once embedded, the embryo secretes chorionic gonadotropin (hCG), a hormone that encourages the production of progesterone.

Home pregnancy kits detect hCG and can therefore confirm if a woman becomes pregnant. To check if you are pregnant, you should wait two weeks after ovulation before undertaking a pregnancy test.

The female reproductive system

The female reproductive system refers to all the female organs that that enable a woman to conceive, nurture and delivery a baby.

  • The vagina is the tract that leads from the outside of the female body to the cervix, the entrance to the uterus.
  • The uterus (or womb) is the muscular organ where the fertilised egg, or embryo, attaches and develops. It is lined with a rich, nourishing membrane called the endometrium.
  • The fallopian tubes extend from the top of the uterus down over the ovaries. The ovaries are the two organs that contain the eggs.
female reproductive system diagram
Understanding the menstrual cycle

The first step for any woman planning to get pregnant is to understand the importance and timing of your menstrual cycle.

Initially, the brain (hypothalamus) sends a signal to another part the brain (pituitary gland) to start the process of ovulation. The pituitary gland produces two critical hormones, the Follicle stimulating hormone (FSH) and the Luteinising hormone (LH), which control the events leading up to and beyond ovulation. Both the hypothalamus and the pituitary gland must be operating normally, and therefore, be communicating clearly to kick-start the first step in ovulation.

In order to get pregnant, you must ovulate or release an egg from the ovaries. It is then picked up and travels down one of the fallopian tubes towards the uterus where, if intercourse has taken place within the last four days, it may meet sperm. Eggs live and can be fertilised for 12-24 hours after being released. Sperm can live and stay active in your body for up to 48 hours.

Hormones also prompt an increase in blood supply to the womb in preparation for implantation. It takes up to five days for the fertilised egg to reach the womb and embed itself in the lining. If the egg is not fertilised, or if the fertilised egg cannot attach to the womb lining, then a period begins.

Calculating your pregnancy window

The exact time of the month for ovulation depends on your menstrual cycle. The time from the start of your period to ovulation (when hormones in your body trigger the release of an egg) varies from woman to woman. On average ovulation occurs about 8-14 days after the day your period starts. However, it can range between 8 and 18 days depending on the length of your cycle. Taking an average menstrual cycle of 28 days, ovulation occurs on days 12-15. Day one is the first day of your period.

The key to achieving a pregnancy is to know your pregnancy window, the time within the month when your body will release an egg (ovulate), ready for fertilisation via intercourse.

New research suggests that intercourse 2 days before ovulation gives the best chance of pregnancy.

Try our online ovulation calculator to help you understand the most fertile time in your menstrual cycle >

fertile window
The male reproductive system

Sperm production starts in the testes, where the hormone testosterone is produced. After sperm is produced it travels along the epididymis before exiting via the vas deferens and out through the urethra as part of the ejaculate. At the point of ejaculation, a man can release up to 300 million sperm into the woman’s reproductive system.

The sperm must travel through the cervical mucus into the uterus and then into one of the two fallopian tubes before they can meet with an egg. Only a small proportion of those make it through the neck of the uterus and on to the fallopian tubes.

The sperm must be actively moving, of normal appearance and of sufficient quantities to be considered normal. It must also be capable of moving through the fallopian tube, where the egg is fertilised.

Sperm can survive in the cervical mucus for 48-72 hours around the time leading to ovulation. Finally, usually only one sperm will find its way to fertilise an egg.

What are the chances of getting pregnant?

There are typically 12 opportunities annually to conceive. Usually one egg is released every 4 weeks. The likelihood of a successful pregnancy for a couple where no obstacles to fertility have been identified and where regular intercourse occurs is:

  • 20% per month
  • 60% after 6 months
  • 80% after 12 months
  • 90% after 24 months
  • 95% after 36 months

When to seek help

There are a number of factors that can affect the male and female reproductive system and therefore your chances of getting pregnant.  If you have been trying to conceive for more than 12 months (or 6 months if you are over the age of 35) without success we recommend you book an appointment with a fertility doctor.

Tips to boost your fertility

Try the following tips to help boost your fertility and help you get pregnant.

Ovulation Calculator

Try our online ovulation calculator to help you understand the most fertile days in your cycle.