Sex with HIV positive person

I had sex with an anonymous partner last night (about 8 hours ago).  He was HIV positive.  He was the one on the anal receive end (I was the top and he was the bottom).  I did use a condom, but the condom broke and I did ejaculate inside of him.  We were actually having sex for about 10 minutes or so.  Should I seek help in taking PEP or what is my risk of exposure to HIV in this situation percentage wise?

[Delgado]

I'm no expert but in a situation where you know the partner was positive, PEP is recommended.

You should go to an emergency room OR an infectious disease/HIV specialist. They will evaluate your risk and prescribe PEP if needed.

You should ask your partner if he is on anti-viral medication. If he was, his viral load should be fairly low, which reduces chance of transmission.

The estimates for insertive anal unprotected vary widely. I have seen anywhere from 0.001% to 1%. The official CDC estimate is 6.56 chance out of 10,000, however this is almost certainly too low an estimate. The figure is believed to double if you are uncircumsized.

I think a good estimate would be 0.004% to 0.05%. With some high risk factors, like the partner has a high viral load and you are uncircumsized, I could see a 1% risk, maybe 2% tops.

This assumes neither of you have any other STDs, like chlamydia, gonorhea, herpes etc. Having one or more of these can double, triple or even increase by 5 times the transmission risk.