1.5 mm = Diameter of pin head
The size of the HIV particle is around 0.0001mm
Now do the math to figure out how many HIV particles will fit on the top of a pin head.
You can see it doesn't take that many virus particles to infect.
It's impossible to say what amount is required.
Presumably, the risk of infection is related to amount of exposure - i.e. the risk goes up the more infectious material you are exposed to. But, remember that the concentraion of HIV in fluids of an infected person is highly variable. The viral load in the blood may be in the 100.000-range for a newly infected person or someone with AIDS or be down to the almost undetectable range (1000-fold difference in concentration this will imply a >1000-fold difference in volume of fluid to get the same amount of virus (i.e. 1 mL of blood from one person might contain the same amount of HIV as 1 L of blood from another) making it meaningless to provide a specific amount required for a given risk of infection.
You don't have HIV. Go back to your original post and read the replies that have been given.
Sorry Teak. Didn't mean to irritate. I had this question in my mind and thought it may be useful for other members also.
But you're right about the paranoia. I think a lot of people (including myself) are suffering from psychological damage of risky behaviour. The mind tends to play tricks. And when in fear, one tends to fall for them. I thought I knew exactly when the condom was put on. But suddenly, today afternoon, I wasn't quite sure. Spent 2-3 hours just recounting the entire experience trying to ascertain the exact sequence of events. And the more I thought, the more doubts crept in. But I think the sequence in my original post is right.
I am just coming out of an eleven-yr old monogamous relationship. My wife and I split up a few months ago. And then, in a drunken haze, I ended up doing this stupid act. I hope I come out of it without any damage other than the psychological scar. And I hope to take this learning into my future and stay clear of risky behaviour. Sex without love is meaningless and deeply unsatisfying. It's better to spend time looking for love than instant gratification.
Thanks Teak.