Question regarding degree of risk for HIV and 10 week test

A little over ten weeks ago, I had a threesome with a gay, married couple who I am friends with and know fairly well.  We all had protected anal (insertive and receptive) sex with each other-- with no ejaculation inside the anus.  We also performed oral sex on each other, and in one case I swallowed the ejaculate of one of them and one of them swallowed my ejaculate. Since then, I have tested negative using the ICMA 1/O/2 HIV test at 3 1/2, 8 1/2 and 10 weeks.  Also, the two guys have told me that they received negative HIV tests about a month after our encounter.

My questions are:
1) Was there an actual HIV risk for the sexual acts performed? If so, how much of a risk and was testing even warranted?
2) Is the ICMA as good, or better than, a 3rd generation ELISA?
3) I know all about the "only 12/13 weeks testing is conclusive" shpiel. Conclusive is a term with a legal bent to it.  I am more concerned with the degree to which I can rely on my 3 ICMA tests out to 10 weeks, if they were even needed. Would further testing at 12 weeks be recommended?

[Teak]

Oral sex is not a risk of HIV transmission. You do not have an HIV concern.

[Teak]

You never had a risk.

[questioningWW]

Are you sure? I have always heard that oral sex, while on the very low end of the spectrum, carries an HIV risk, as well as that protected anal sex can still have some, albeit very low, risk. I understand that my 10 week negative and their +-4 week negatives provide some strong evidence to the contrary of their being any risk, but would there still not be some theoretical risk involved in the encounter? I tend to be a big worrier about these kinds of things, which is why I am always safe in my encounters, but some of what one can read on the internet can make you scared of even brushing up against someone.  Just for my piece of mind I am going to go ahead and get a test at 12 weeks, but do you think there is anything I should be worried about all things considered with 3 negatives out to 10 weeks? I know that HHH and his colleagues would say that after an 8 week negative it should be "conclusive" but I am not sure I am ready to 'buy' into that as of yet.

[Teak]

Oral sex is not a risk of HIV transmission. You do not have an HIV concern.

[questioningWW]

Thanks for your responses...but since I have asked,

Do you know what this ICMA test is? It is a "3rd gen" test. Is it an ELISA?

Also, and not to sound confrontational whatsoever, but why do you seem so steadfast in your pressing of the 12/13 week conclusive when the overwhelming amount of evidence points to a 6/8 week conclusive?  This is an area I am interested in out of intellectual curiosity more than actual worry, but hey, worry is always there.