Itching in my urethra and slight yellowish discharge. no pain when urinating. any advice on what this could be?

Gonorrhea or NGU: Urethral discharge is just about always due to an STD. You have either gonorrhea or nongonococcal urethritis (NGU) -- probably NGU since gonorrhea usually is painful, NGU often "itchy" but not painful. About one third of NGU is caused by chlamydia. You need to see a doctor promptly for exam, testing, and treatment. Your recent sex partner(s) also need evaluation and treatment. Good luck!