Hello, I Have A Question Regarding Possible HIV Exposure. Three

Hello, I have a question regarding possible HIV exposure. Three nights ago, I was engaging in heterosexual vaginal intercourse with a male of unknown status. We were using a condom, but right before he ejaculated, he pulled his penis out of me, removed the condom, and ejaculated on my buttocks. I then felt his semen drip down between my butt cheeks and onto my anus. I was so concerned that the very next day, I went to an urgent care facility in order to get PEP treatment and was put on a 30 day course of Truvada and Reyataz. However, I'm still terrified. Was I at any risk for HIV since the exposure took place outside of my body? How effective is the PEP treatment? How soon can I be tested?