Can antibiodics and doxycycline eliminate chlamedia right away? do i get more doses if i don't feel a change?

Few days: You can expect it to take a few days. There may be the need for addition treatment. Always practice safe sex.

Not right away: The antibiotics take some time to work; the reason Azithromycin is given as a single dose is that it has a huge half life of 50-72 hours, so you will have several days worth of antibiotic effect in your body after a single dose. The infection should be cured by 7-10 days.