False positive chlamydia test?

Has this happened to anyone? I tested positive last week, I am also pregnant and tested negative in June. Neither me or my partner has been unfaithful. I am so confused.

EDIT: husband is getting tested today. We’ve been married for four years, I have regular std checks every year with my Pap smear, and also twice with my precious pregnancy. Neither of us have any symptoms at all of having an std