I've never used the map. But I agree with blaze on the std issue. Go ahead and get tested now. Then go back in 3 months and then go back in 6 months.
It takes anywhere from 3-6 months for hiv/aids to show positive on a test.
If everything comes back okay after 6 months (unless you engage in risky behavior between that time) you should be okay.
Good luck...I hope everything works out for you.
As far as the map...I think it has a pretty high effectiveness rate.