Sometimes, and very rarely, my urethra will have random pains. could it be from how i am sitting or something or serious that i should get tested?

Just neglect it, only pay attention if pain is persistent, exacerbated with voiding or pain is associated with urethral discharge or bleeding.

Urethra extends from the neck of the bladder to the tip of the penis and in normal sitting position is not impinged upon. Your pains might be due to another reason. If the persists you first need to be checked and then tests done only if needed