Thank you for the clarification.
A level of 0.37 only means that it is negative. Whether it may increase if you test again is dependent upon the clinical situation, not the level, which leads to the remainder of your question.
The antibody and p24 test at 10 days is only fairly accurate, while the third generation test at 22 days is moderately accurate. With the sensitivity of the current tests, the average time to a positive result is about the 22 days after exposure. However, since it is the average, that still means that a significant percentage will be above the average. Therefore, a negative test at 22 days is reassuring, but is not considered conclusive. The current recommendation when testing for HIV following a worrisome exposure would be to repeat the test at 3 months. The result at 3 months would be the result that is considered conclusive.
It is important to note that the risk
of a single encounter is lower than what most people realize. The average risk to the male of an unprotected encounter of penile-vaginal sex with an untreated HIV positive female is 0.05%, which also means that 99.95% do not get infected. If the partner is of unknown HIV status or is being treated, then the risk would be even lower. There are different risks for other types of sexual encounters. With the negative result at 22 days, then the risk for this type of encounter would be down to 0.025% or less.
To cycle back to the interpretation of the level of 0.37 - if the result at or after 3 months is 0.37, it would only mean that you are negative, and there is no risk that it may increase to a positive level if repeated after that point.
If I can provide any clarification, please let me know.