There are lots of options when it comes to contraceptives, some you can get from your pharmacy and others require a visit to your doctor.
Family Planning is a great resource for all your contraceptive option.
NSW: https://www.fpnsw.org.au/ QLD: https://www.true.org.au/ ACT: https://www.shfpact.org.au/ VIC: https://www.fpv.org.au/ TAS: http://www.fpt.asn.au/ NT: http://www.fpwnt.com.au/ SA: https://www.shinesa.org.au/ WA: http://shq.org.au/
Contraceptives discussed effectiveness:
Ovulation Awareness (FAMB): 75-99.6%
Condoms: - Female 79-95% - Male 82-98%
Breastfeeding (LAM): 94-99.8%
Copper IUD: 99.2%
Hormonal IUD: 99.8%
Source: NSW Family Planning Contraceptive Choices.