The ‘window period’ is the time period between potential exposure to HIV e.g. sex without a condom, and the point when the test will give you an accurate result.
Tests done too early may not be accurate.
The HIV blood test is unlikely to detect HIV if you have contracted it in the last 45 days. However, if you are worried about a specific risk within the last 45 days, you should still do the test, but we recommend that you purchase another test to do 45 days after the last exposure.