Most likely both semen and the urethral secretions themselves can transmit chlamydia, but this has never actually been studied. If you are getting at the possibility that you didn't infect your partner because you didn't ejaculate, forget it. She is at risk. The chance of infection probably was lower than otherwise because of the brief exposure. But it was plenty high enough to infect her. She needs to be tested and treated (without waiting for her test result), and you have an absolute ethical obligation to inform her that you were infected when you had sex. Don't let her down.
Best wishes-- HHH, MD