Thanks for writing.
When using the 4th generation HIV test we estimate that greater than 95% of individuals will have a positive test result by 6 weeks, with greater than 99%+ having a positive result by 3 months.
The time it takes for a positive result to show up is different for every individual. Some people will show up right away, and others will take longer. Because of this, it’s hard to give a specific window period that will work for everyone.
However, we can say that a test at 6 weeks after exposure will be 95%+ accurate, with a final test after 90 days (3 months).
You can be very confident in a test a 6 weeks after exposure, and test again if you are still concerned. There is no need to repeat testing after the 3 month test.
Please feel free to submit another question if needed.