whenever i have sex i always wear a condom, i recently had a urine test for chlmydia the result was negative!.. however I have had oral sex from a female, i wasn't wearing a condom.. i do not have any symptoms or problems in my genital area, also whenever i blood donate they check my blood for HIV, Syphillis and hepatitis the results are always negative..is there any need for a sti test? thanks