I just had surgery and I had to be on antibiotics for a week. I got my period the day after my surgery. I was supposed to start my next pack of BC last Wednesday but I decided not to since I was still taking my antibiotics and it would be pointless anyway since they would counteract each other. So, I'm starting my next pack of BC one week late. Will this effect my period in any way besides making it come one week later? I'm taking microgestin fe 1/20 for over a year now. Thanks