Pregnancy occurs as a result of sexual intercourse when semen flows out of the penis during ejaculation and enters inside the vagina. Pregnancy can happen even if the penis is pulled out before ejaculation as the small amount of semen in pre-ejaculation fluid can come into contact with the vagina.

The sperm then travels up the vagina moves through the cervix (neck of the womb) and uterus (womb) and then into the fallopian tubes where it fertilises an egg. Only one sperm fertilises an egg. The fertilised embryo then moves down the tube into the uterus where it attaches to the membrane wall and grows. This is the beginning of pregnancy.

Preventing Pregnancy

If you have sexual intercourse and wish to prevent pregnancy then you will need to use a form of contraception. A range of options are available to you. It is important to remember that while the contraception may protect you against pregnancy, only condoms can prevent pregnancy and protect you against HIV and other STIs.
Some of the contraception options available are explored below. You will need to choose an option that best suits you and your partner's needs.

Some contraceptive options are better at preventing pregnancy than others. All contraception is more likely to work if it is used correctly. There are advantages and disadvantages to all the contraception options available.
For more information on contraception options you need to talk to your doctor. Family Planning Factsheets on contraception are also available online.

The Pill

The Pill has been available in Australia for many decades. It must be taken every day as directed. If you miss just one pill and have sexual intercourse, then you risk pregnancy. Until you have taken the Pill for seven days in a row you need to not have unprotected sex. The Pill is one of the most effective methods of birth control. The Pill is only available with a doctor's prescription.
Mini-Pill is also available. It needs to be taken at the same time every day. The Mini-Pill is ideal for women who cannot take oestrogen, but is not quite as reliable as The Pill. It is also only available with a doctor's prescription. 


As well as male condoms, female condoms are now also available. Female condoms fit inside the vagina and completely cover the walls of the vagina, cervix (neck of the womb) and some of the vulva (the outer areas of the vagina).
Female condoms are put on before sex and protect against infection and pregnancy, though, like condoms for men, they can only be used once.
Both male and female condoms, if used correctly, can prevent against pregnancy, HIV and many STIs. Not all condoms are made of rubber so people with a latex allergy need to consult their doctor to find the right alternative. 


The diaphragm is a rubber dome which fits inside the vagina, covering the cervix. It is held in place by the pelvic muscles. The diaphragm acts as a barrier for the sperm getting into the uterus (womb). Your doctor can provide a 'fitting' and show you how to use it correctly. It needs to be inserted before sex and must stay in place at least six hours after sex. It can take some practise to fit it correctly, but it can be cleaned and reused. Its effectiveness depends on how correctly it is used. 


Implanon is a small implant, containing the hormone progestogen, inserted in skin of the upper arm and can protect against pregnancy for up to three years. If inserted correctly it can be very effective in preventing pregnancy as it doesn't rely on remembering to take daily pills. 

Depo-Provera Injection

Depo-Provera is an injection of the hormone progestogen given every 12 weeks. It stops ovulation and is a very effective method of contraception. 


The intra uterine device (IUD) is a device placed in a woman's uterus. The IUD prevents fertilisation of the egg. The IUD is inserted by your doctor. It provides a long term reversible contraception option. It is a very effective contraception and can be easily removed by your doctor. Some IUDs also reduce heavy bleeding. 

Emergency contraception

Emergency contraception reduces the chance of pregnancy after unprotected sex.
You can take emergency contraception when contraception was not used, a condom broke or slipped off, if you were unsure if a condom was used, oral contraception pills were missed, if you think a diaphragm dislodged, etc. It needs to be taken within 72 hours (three days).
To find out what methods of emergency contraception are available, click here Family Planning Factsheets  

How do I know if I am pregnant?

Some of the first signs of pregnancy are:
  • a missed period
  • nausea (feeling queasy or sick)
  • sore or swelling breasts
  • unexplained tiredness
  • frequently urinating
  • mood changes
  • vomiting
  • feeling bloated.
The signs of pregnancy vary from woman to woman. Having one of these signs does not necessarily mean you are pregnant. The only way to be certain is to take a pregnancy test (2.5.4).
Sometimes your period can be late for reasons other than pregnancy such as:
  • stress and fatigue
  • hormone disturbance
  • exercising too much
  • losing lots of weight
  • gaining lots of weight
  • coming off The Pill.

How do I test for pregnancy?

If you think you are pregnant, you need to have a pregnancy test.
Two options are available for testing.
  • Visit your local doctor, FPA Health, youth health centre, women's health centre or Aboriginal community controlled health services.
  • Use a home pregnancy test. Such tests can be purchased from large supermarkets or pharmacies. The tests are quite accurate but you need to follow the instructions exactly and ensure you don't take the test too early. It is important to confirm results by a follow-up visit to your doctor.

If I test positive...

If you test positive you need to discuss pregnancy care with your doctor. They can talk to you about your diet, smoking and alcohol, as well as address other health concerns you may have. Having a baby is a big event and it can mean a lot of changes to your current lifestyle.
If the pregnancy is unintended then you need to seek professional help sooner rather than later. Again your doctor will be able to assist. Unintended pregnancy can happen to any sexually active women and in many different situations, even to women who are using contraception.
If the pregnancy is unintended you need to explore all your options. It may be important for you to talk to your partner, friends and family whose opinions you trust and support you value. Make sure you make an informed choice about whatever action you decide to take.
If you test negative, it may be a big relief if you weren't intending to get pregnant. It is important that you consider your contraception choices to prevent any future unintended pregnancies. Talk to your doctor to figure out what contraception is best for you.
Current as at: Thursday 7 March 2013
Contact page owner: Centre for Population Health