In theory, there's a chance. In reality, there's not much of a chance. Most experts don't think you need to test after a single act of unprotected oral sex.
If it was me, I wouldn't worry.
If you decide to test, you should test for gonorrhea, chlamydia, syphilis, NGU and hsv1. Again, though, your chances are very, very, very low, and you don't need to worry.