Okay, here is the real deal:

1) Uncovered vaginal sex is actually low risk on a one time encounter. People that develop HIV from vaginal sex almost always do so after numerous exposures. It is difficult (for obvious reasons) to determine the exact risk from vaginal exposure, however numerous studies have placed it in the 1:1000 to the 1:10000.
2) Uncovered anal sex is extremely dangerous and may be in the area of 1:30 to 1:150.
3) It is much harder for a female to male transmission than male to female (think about where the fluids go).

Should you see your doctor? I would say yes, but you don't have to run there. It takes a 6 month post exposure HIV test to rule out HIV infection, although 90% of people will seroconvert within 3 months so you can get one then if the wait is too long.

Remember, ANY sexual encounter presents a risk to the people involved. Reputable sexual workers are probably far down on the risk category because they regularly use condoms. Compare that to Maxim's survey of college girls that have 65% not using a condom on a one night stand.

Bottom line (from a truth standpoint, and not a politically correct standpoint), I wouldn't worry that much about it (from a sexual disease standpoint, not from a pregnancy standpoint, thats a different discussion). Just don't make it a regular occurance

If going to your own doc is unsettling in any way, head to AIM (www.aim-med.org).