Hi doctor, I had unprotected sex with sex worker before
Late seroconversion practically is none...
Late seroconversion is noted theoretically. But in practical cases, I haven't seen late seroconversion for the last 15 years. So if all the test after 1.5 years returned negative results, then you need not be worried about seroconversion and HIV infection.
Hope this answered your question. Let me know if you need clarifications.
Proceed with your plan...
You can proceed with your marriage plans. As your test results are negative, you should forget the instant and go ahead with your life and plans. Avoid repeating the mistakes again.
Hope this helps. Let me know if you need any further clarifications.