Talk to General Physician on Inquiry About HIV I & II Test Results

I doubt that i had hiv on August 10, 2023, so i got my anti serum hiv I & 2 from chughtai lab on 20 september 2023 (after 1 month and 10 days). the result was non-reactive and the value was 0.15. Just for the confirmation, I got my anti serum hiv I & 2 again on 14 october 2023 from the same laboratory, now the result is non reactive but the value is higher than before which is 0.17,, if the test is negative, and i m not infected with hiv, then why the value is high 2nd time? 1st test shows 0.15 and 2nd test shows 0.17