What are the risks of HIV infection for the passive partner of oral sex?

My question is about AIDS/HIV: I had a sexual affair that lasted two-and-a-half months, and, unfortunately, I was not using condoms. I happen to know nothing about my partner's previous sex life. I know that, for a test to show something, you must wait for six to nine months. I would like to know whether, provided that I am infected, I will experience any symptoms in this six to nine month period? Is it possible to have the virus and not have any symptoms or indications all this time? Right now, I am a graduate student and I am experiencing anxiety, fatigue, sleepiness, weight loss (three to five pounds in the last two months). Are these related to the disease, or is it just in my mind?

I am curious about double penetration (two penises in one vagina). Because of the increased friction, even if both men are wearing condoms, is there more of a risk that the condoms would break?

I currently use NuvaRing for contraception. Because the ring slowly emits hormones into the body via the vagina, my partner and I are wondering whether he will have an unhealthy amount of contact with these hormones during oral sex. Thanks.

What are the signs of an advanced case of syphilis, say twelve years down the road? Is treatment still possible or is it too late? I have reason to believe that I've been infected that long, and denying it. Would I still be contagious? Would I have been after five years?