I thought i may have had a std and was given athithromicn and suprax (cefixime).7 days after taking the meds i tested negative.could i have had an std?

Hard to say: We usually do that study before, not after any antibiotic treatment.You might continue to shead dead germs after treatment and the tests rely on the germ proteins that can persist for a while after death but not always.We also don't know what you were tested for and how. You may still have a STD if they did not test for it specifically, but many of those cannot be cured anyway.