I don't know what her discharge was - it might be natural lubrication, maybe a bacterial vaginosis infection, but it's hard to say.
In any case, any infections spread through fluids - gonorrhea, chlamydia, HIV, hepatitis B, trich, etc. - are all non-issues because the head of your penis was covered by the condom. If her fluids get into your urethra, that's how you'd get those infections if she had one.
Herpes, hpv and syphilis are all spread by direct, unclothed skin to skin contact. Those aren't associated with discharge, though.
If the oral was unprotected, you could get gonorrhea, chlamydia and syphilis if she has those orally. If she has oral herpes type 1, and you don't already, you could get genital herpes type 1. The risks are much lower for oral, and most experts don't think one act of unprotected oral even warrants testing.
I don't think you need to worry about this, and testing is always a good idea if you are sexually active. If your local Planned Parenthood doesn't offer herpes testing, that's okay. There are a decent amount of false positives with herpes type 2 blood tests, so unless you get symptoms, I wouldn't test.