I was diagnosed with chlymidia and was given two pills of azithromicine and was told to wait a week before having sex again. However the guy I like came back from the army and really tried hard to have sex with my I said no at first but eventually gave in. It was four days after being treated. How likely is it that he is now infected if he wasn't prior? Should I be very worried?
There is a chance you may have passed on chlamydia. First off, it's not always cured the first time around. It fails about 5% of the time and you'd need another antibiotic.
Second, you are told to wait a week for a reason. No drug works instantly. It takes time for the drug to get into your bloodstream and become effective. Even a weakened infections can be passed on.
You should have a follow up and your partner should be tested as well.
Just a comment: If you'd told him you had chlamydia beforehand he probably wouldn't have had sex with you - and you should have. To knowingly pass along an STD is a criminal act in many locations.