Yep, best bet is to talk to your family physician or check out reputable resources online.
Don't listen to old wives tales.
It's not impossible to get an STD from unprotected oral -- it's not enormously likely, but it's not impossible either. Risk is probably greater in male-to-female transmissions rather than female-to-male.
You must decide for yourself what level of risk you're comfortable with. Educate yourself -- and not with anecdotal chatter, but solid reputable medical resources.
..c..