I can't find anything with really current estimates, but an older stat (2006) says that 10-15% of men won't get symptoms of gonorrhea, and 80% of women won't. I don't know how accurate that is, but it sounds about right.
You might have white blood cells in a dipstick urine test if you had gonorrhea, but that's not the best way to test for STDs. Nothing would show up in a regular blood count test.
The other aspect that you didn't ask about but is relevant to you is how long a man would go without symptoms. You received oral sex last year, so I'm assuming this was at least a year or so ago. It would be very unlikely that you'd go this long with no symptoms.
I sense that you aren't going to be able to move beyond this. You can get this test on your own, but you'll have to self-pay - https://www.stdcheck.com/gonorrhea-test.php (If you aren't in the US, let me know - I know of some similar places in other countries.)