Thanks for the great advice doc!
Welcome to the forum.
Oral sex is safe sex -- not entirely free of STD risk, but a lot lower risk than unprotected vaginal or anal sex; there is low risk for all STDs and zero risk for some, including HIV. I generally do not reocmmend STD/HIV testing after exposures such as yours, and if I were in your situation, I would not be tested and I would continue unprotected sex with my wife without fear of infecting her with HIV or any STD. If you want to add a bit of safety, wait for 7-10 days; if by that time you have had no symptoms (penile sores or discharge), you can safely assume you were not infected.
I hope this has helped. Best wishes-- HHH, MD