I used a porta-potty at a local bus station, which was thoroughly disgusting - despite my needing to go. I urinated into the toilet, which contained fecal matter, toilet paper and other things typical to a porta-potty, and tried to stand back as far as I could. I also have a blister on my thumb which is healing, and I don't know if by touching the door that would increase a risk. Is there any HIV risk in using this type of a public restroom? Also, hypothetically, could something have dripped down onto my penis from the roof of the porta-potty and infected me? I didn't notice anything, nor have I noticed an open wound on my penis. How does HIV transmission occur through a bodily fluid getting into a cut, if at all? Thanks.