What procedures must be taken to ensure not contracting AIDS after an illicit sexual relationship, and how can obsessive-compulsive disorder related to the disease and marriage be overcome, especially given that the initial test result was negative?

One who repents from sin is like one who has no sin. Allah forgives all sins, and Allah may transform evil deeds into good deeds for whoever repents, believes, and does righteous deeds. There is no blame upon you in getting married as long as the tests have proven your freedom from the disease, and do not be concerned thereafter with the accuracy of the tests. For if you had married before the tests, you would not have been mistaken, because Allah has overlooked error.