"Yoy", who responded (below) before me, has me down pretty well.
First, you probably are entirely immune, and certainly highly resistant, to genital HSV-1 if exposed to someone's oral infection. (For the calculation below, assume a 10% chance--which actually is much too high.) Second, asymptomatic shedding of HSV-1 by orally infected people isn't all that common--not as frequent as for genital HSV-2, for example. (Assume a 1% chance.) Third, 3 weeks is too long a delay for initial herpes to show up. Occasionally it is that long, but most new infections cause symptoms within 3-10 days. (Assume 10% have symptoms delayed 3 weeks.) Fouth, your symptoms are not typical for herpes, as you suggest yourself. (Assume a 10% chance.)
So in order for you to have newly acquired genital HSV-1, 4 highly improbable events all have to come up the wrong way. What are the odds? Using the hypothetical figures above, it's 0.1 x 0.01 x 0.1 x 0.1 = 0.0000001. That's one chance in a million. That, in turn, is less than the chance you will die in some sort of accident in the coming week.
Of course, there is another possibility: Your existing HSV-1 infection might be genital, not oral. If so, you might have had a recurrence that became apparent after you irritated a spot where a herpetic recurrence was on the verge of starting. I doubt this, but it is far more likely than the chance you have a newly acquired genital HSV-1 infection.
Your partner's armpit skin rash is irrelevant to your risk level. If SHE is concerned about it (not you), she should see a health care provider. If she really has a cluster of blister-like lesions, herpes zoster (shingles) is much more likely than HSV.
Good luck-- HHH, MD
Let me see if I got this right-
you get tested and + HSV-1 but you think it is pre-existing and not related to ou sexual activity with your friend. Ok
Three weeks after test, another bout of oral sex from your friend who is HSV 1 + orally.
THe doc will tell you that since you already have HSV 1 you cannot get it again. So, the new sore would most likley not be HSV 1 on your genitals.
The symptoms do not sound like HSV-HSV does not almost heal over night. Doubtful you have it.
Could you get HSV-2 from your friends oral contact. THe doctor will have to answer that, but my memory seems to indicate that the FAQ section says you get HSV 1 form oral not HSV 2. But I'ld wait for the doctor.
Also, the doctor cannot give you 100% certainty that it is safe to have sex with your wife. YOu had oral sex with another person. You could get gonohrea or syphilis. Rare, low risk, maybe very low risk, but not no risk. With lack of symptoms you may be home free, but syphilis could take 3 months to develop symptoms. Again usually sooner, but do you want to be the exceptsion and pass that to your wife. It sound like you are three weeks from your last experience. You could get tested to rule all that out at this time I suspect. You see you are not dealing with an issue of whether you have it, but whether you want her to get it and whether you get caught.