Are there any over the counter antibiotics for chlamydia?

I do not think so: You probably need a prescription after getting tested by giving urine and / or blood samples to the lab.

Not in the US: Antibiotics are considered potentially dangerous if used without proper evaluation & as such are prescription only in the US. If you are a sexual contact of a diagnosed case sometimes their doc will authorize treatment without a visit. Under most circumstances you need to be tested for other STD's that are often passed at the same time so all can be treated at once.