What is the best pregnancy test to take at home?

In your opinion, from personal experience or word of mouth, what is the most accurate in home pregnancy test? Any comparisons and/or prices of the tests would also be appreciated. Do you know how soon you can take the tests before your first missed period?

What is the best way to prevent pregnancy after having sex?

What is the best way to prevent pregnancy after having sex? Today is the 5th day after having sex with my boyfriend. Is there any medicines (asides from pills, because pills will only prevent pregnancy if you take it right after having sex) that will prevent pregnancy???