birth control spotting?

mena

hi guys! i just had a question, i started birth control this month and im nearing the week i start the placebos, but not there yet. ive been on time everyday and i started spotting a little bit and getting kind of bright red but mainly pinkish spots when i wipe. i know that sometimes antibiotics can cause breakthrough bleeding and ive been battling a sinus / ear infection and i’ve been taking antibiotics. is it just the antibiotics doing this to me, and is my birth control less effective cause of this?