Dear Doctors, I'm sorry to be here again. I've been working on myself, but I fell back into a situation I don't want to be in.

I had sex with a woman, even though I am a heterosexual man.

We had unprotected vaginal sex, as well as oral sex, her to me and me to her.

She kindly took a 4th generation HIV test with me, and we both tested negative. (This was two days after having sex with her.)

She admitted to having had unprotected sex with other people before me. What is the likelihood of transmission in this case? It may have been 7 or 15 days ago when she had unprotected sex with other people before me; she couldn't tell me.