I've never thought about it or had such a question. As far as I know, it wouldn't cause any harm. But surely you can wait a day or two, so why press your luck?
Thanks, I have one last question.
Is it safe to masturbate while you have an infection like Gonnorhea?
Not too early. Testing for urethral STDs is valid any time there are symptoms, and within 2-3 days even without symptoms.
Thanks, I actually meant is tomorrow to early to get tested.
Thanks again
Gonorrhea is most likely; it's the only urethral STD whose symptoms start so soon. Chlamydia or NGU are possible, but symptoms usually start 1-2 weeks later. Also, chlamydia is rarely if ever acquired from oral sex, but gonorrhea often is. The vaginal sex could also be the source if the condom wasn't used properly or if there was an undetected condom failure.
Your symptoms are only possible from an infection directly to your penis; performing oral on your partner is unrelated. Cunnilingus is low risk for oral infection, and if you have urethral gonorrhea, the treatment will be effective against oral if you have it. So oral testing isn't really necessary.
Tomorrow isn't too late to be examined and tested. Whatever you have will probably still be easily diagnosed any time in the next week or two. But the longer you wait, the more pain you may experience, as well as each day increasing the risk of complications like epididymitis, disseminated infection, etc. You should be seen today or tomorrow if possible.
Good luck.
Also, what other STD's could it be?