SMZ-TMP DS + YAZ BC

Hi everyone, I’m sure this is a common question, but I have a sinus infection :( and was prescribed this medication for it. I’ve been on BC for 3 months. I’ve heard that it’s not true that antibiotics can reduce the effectiveness of BC, but my pharmacy still told me to be cautious, use secondary method, etc. I guess I’m looking for certainty here! If anyone has specific experience with this antibiotic that would also be great.