I had sex with a girl so i went to the doctor 2 hours later to get tested gave them a urine sample and they put me on doxy the same day. i came back positive 2 days later for chlamydia. and sex on the 5th treatment day did i pass it to another girl?

Probably you did not catch chlamydia during the exposure mentioned; two hours is much too soon for the test to be positive. Conceivably, your positive result was because your urethra contained a small amount o your partner's vaginal fluid, but more likely you were infected previously. However, 5 days of doxycycline probably is sufficient to prevent infection to your next partner.