You can get what’s called a Duo test at 4 weeks after poettnial exposure. This test looks for both antibodies and antigens. The standard antibody-only test has a window period of 12 weeks and it’s recommended you go back to confirm the result at that time. However, the duo test is highly accurate (around 98%) and it’s unlikely the result would change. American guidelines state 6 months, however this would only be necessary if you have some kind of autoimmune disorder. If you have an autoimmune disorder it is something you would be aware of so for the vast majority of people an accurate result can be found at 12 weeks and a very good indication at 4 weeks.If you always use condoms and if you understand how HIV is transmitted and practice safe sex you will not be at risk of HIV infection. This fear you have of HIV transmission indicates that perhaps it would be useful to talk with a health adviser or counsellor to help you learn to control this anxiety. You really won’t be at risk if you know how to protect yourself.