Do get tested if you have had unprotected sex with anyone other than your committed partner (and yourself).
Do get tested if you didn't use a condom, the condom broke, or if the condom was ushered in after the movie started.
Do get tested if you have any doubts.
Do get tested for HIV and Hepatitis B as well, if any of the above applies.
Do wear a condom.

Don't ignore any symptoms; denial isn't an effective treatment.
Don't be embarrassed to tell your doctor. Or be embarrassed, but tell him/her anyway.
Don't be an idiot -- use a condom.