What Are The Tests For Chlamydia?

Hi, I have a question. I went to the doctor 3 weeks ago, I thought I have an urinary infection. They took my urin and tested it, in few days told me it was negative for infection. Week later I went for my pap smear and my doctor told me I have a vaginal infection. She took my urin again to test it and she said she will test it also for Chlamydia. Wouldnt Chlamydia already show on the first urin test?