It could definately be each other's liquid (for lack of a better word) that is irritating. I know when giving oral to my boyfriend, my throat feels coated, raw, and burn-ish afterwards. Drink some liquid right after, generally I'll takea sip of a soda it hels the best. It'll also get rid of that damn taste lol.
Symptoms would not start the next day and most of the time oral gonorrhea shows no symptoms. And if symptoms did show they do not come and go when doing the act.
If you want to get tested get a throat swab done.