There is no debate on fourth Vs sixth week for a IV Gen.
As reassured by diver58 for a low risk exposure a IV Gen is conclusive at 4 weeks and as correctly pointed out by chima7, you had no risk. Hence, it is unnecessary for you to worry about information regarding any kind of HIV testing.
Your actual issue is cheating on your wife, which is leading you to confuse your guilt with other emotions, see a therapist for it, you don't have HIV, you can't pass it on to your wife since you don't have it. We have established that you don't have an HIV concern. Please accept support offered and move on.
The risks of HIV transmission in adults is to have unprotected vaginal or anal sex where penetration occurred or sharing IV drug needles. Those really are the only documented cases that have been proven to spread HIV. It's actually a very fragile virus. Hand jobs do not transmit HIV. You didn't need to get tested but your negative test confirms that you don't have HIV.
Your risk never existed, therefore your test result will always come Negative.... Even if there was a risk, 4th generation test is conclusive any time four weeks after the exposure