We recommend waiting twelve weeks after the risky encounter because HIV or syphilis may not show up in a test done before this time. If you are a gay man and have had unprotected anal intercourse in the last 72 hours you may be eligible to have PEP (post exposure prophylaxis). To learn more about this you can call the NSW Sexual Health Infoline on 1800 451 624
or attend the local emergency department of your nearest hospital. may not show up in a test done before this time.