At this time, no matter what sort of test you have, the results will be definitive and when you see that your test result will be negative you can then be sure that you did not give your wife HIV
and the both her recent illness and your child's thrush are coincidence, not HIV
The exposure you describe is low risk. Although you do not remember all of the encounter, what you remember was condom protected and thus no risk. Why would other sex be condom protected if your first sex was not?