Just in case, this might reduce your worries and of many more people.
These are some very recent comments (all were made 3 months ago, 2020) by the expert Dr. Hook:
"Yes. There is no meaningful difference between a 40, a 42, and a 45 day test. Further, just to hopefully provide further comfort still, more than 99.9% of tests that are going to become positive are positive by day 28. Neither of us has ever seen a person whose test was negative at day 28 go on to become positive in the next 2 weeks".
"Neither Dr. Handsfield nor I have ever seen or heard of a person who converted their 4th generation HIV test from negative to positive after 28 days"
"By 28 days nearly all (well over 99%) persons who have acquired HIV will have positive tests. Our colleagues at CDC tell us that there are "a few" persons who developed positive tests after 28 days but this occurs so rarely that there are no scientific studies which precisely define the frequency. None of us on this forum have ever seen or heard of such a person."
The "90 day" statement is outdated, and only applies to 3rd-generation tests, which are antibody-only tests. Your test was a 4th-generation test, and you have tested conclusively negative for HIV. No further testing is needed. You don't have HIV.
Duo test is conclusive at 4 weeks not 90 days,your test at 40 days with the duo test is conclusive that u dint not get infected from hiv at all.
Sorry typo : unprotected sex in first line :(