You do have some risk, but most experts feel that one act of unprotected oral sex doesn't warrant testing.
You had protected sex, and unprotected oral, so you're at risk for gonorrhea, chlamydia, syphilis, HPV and genital herpes, both type 1 and 2.
Condoms offer significant, but not full, protection against the infections that are spread by direct skin to skin contact - syphilis, herpes and herpes type 2.
Since you received oral sex, you'd also be at risk for genital herpes type 1, if you don't already have oral hsv1.
I don't know how long your oral sex was, but the briefer, the lower the risk.
If you feel like you won't be able to move beyond this without testing, then test now for gonorrhea and chlamydia. You can test for syphilis at 6 weeks.
There is no test for men and HPV.
The tests for herpes are up to you, but without symptoms, I wouldn't test. The hsv1 test misses 30% of infections, and the hsv2 test has a fair number of false positives. Additionally, the blood test can't tell you where the infection is - if you test positive for hsv1, you don't know if that's a pre-existing hsv1 oral infection, for example, or a new one.
Remember that oral sex is lower risk than vaginal or anal sex, and that guilt doesn't equal risk.
It does seem like you feel bad it happened. Protected sex with condom is safe and would not worried about that. Oral sex does pose some risk but you had brief oral sex. You have no symptoms of anything? When that is the case, some elect not to test. but since you are in a committed relationship, are you seeking the time frame for routine testing just to check?