Because I am a very anxious person, I went down a rabbit hole about getting HIV from this woman. Eventually I called a virtual doctor and asked for PEP. I started taking it 66 hours after exposure. I am on day 3. So here's my question finally lol - is PEP really effective at this point? (https://www.aidsmap.com/news/mar-2020/new-pep-studies-revive-interest-post-exposure-prevention) - this study showed that there was no benefit to taking it after 48 hours.  I ask because I would like to get tested sooner and apparently the NAT tests aren't accurate when taking PEP. I don't think I mentally can handle 28 days. Especially with this study in my head. 

I would have strongly advised against PEP in this situation. First, it is statistically unlikely your cunnilungus (oral-vaginal sex) partner has HIV, which is rare in women in the US. Second, there has never been a scientifically documented case of HIV transmission by cunnilingus; and in general, it is rare to get HIV from any kind of oral exposure. The possible blood contact makes no difference:  the amount of HIV in blood is no higher than in vaginal fluids.

You should disregard the study you cite. The extent to which the results in nonhuman primates are valid in humans is uncertain. The effectiveness of PEP in humans is very difficult to study and there are no firm data on effectiveness at any starting time after exposure. There is strong expert consensus that it's nearly 100% effective within 24 hours and wanes to somewhere around 50% effective at 72 hours. It's fair to assume it would be only modestly effective at 66 hours. However, since you were at near zero risk anyway, the chance you have HIV is under one chance in millions.

You touch on one of the downsides of PEP, namely your emotional ability to handle a month of uncertainty before conclusive testing. In fact, it's more like 6-8 weeks, i.e. 2-4 weeks after completing PEP. Without treatment, you could have a conclusive HIV RNA PCR test at 11 days after exposure; or to provide a margin of error, maybe 2 weeks after the last dose.

We do not advise directly about treatment, but you might have a discussion with the prescribing clinic, or your personal physician, about whether or not to continue treatment. Putting things in personal terms, if somehow I were in your situation, I would never have started PEP and would be continuing unprotected sex with my wife with no worry about infecting her. I wouldn't even be HIV tested. After all, you're certainly not going to be the first person in the world who acquires HIV by cunnilingus.

In other words, you really shouldn't be at all worried. I hope these comments are helpful. Let me know if anything isn't clear.

HHH, MD

I'm not entirely clear whether you have started PEP. If not, an RNA test 11 days after exposure will be conclusive. If you've taken one or more dose, it would be best to wait until 14 days after that dose. However, it really doesn't matter, since there is no chance you caught HIV anyway, for the reasons discussed above.

That winds up this thread. Best wishes and stay safe.