My boyfriend and i both had chlamydia. he was tested and treated before me. we waited over 7 days since he was tested positive but im not sure if it was 6 or 7 for me. he was retested 3 days ago and was clean. how much at risk are we?

Hard to guess: Re-infection is possible, as there are no guarantees in life except "death and taxes." Usually, after full treatment, each patient can get retested to be confident that neither still carry the germs. Because tests are not able to detect all residual cases, there is a small chance of reinfection even after a negative test. That's why the best defense is never to catch an STD to begin with.