Mixed urine analysis result?

I just got a call from my doctor saying my routine urine analysis test came back with mixed results, meaning there were some unexpected bacterial cultures on the report (could have been contamination during collection, or could be a genuine result from the test).

I don’t have any symptoms of a uti (no pain or burning down there) but my doctor is prescribing antibiotics just in case. He said this can be a cause of early miscarriage (I’m 13 weeks now).

Has anyone else had something similar happen?
I’m super worried now after he told me that…