I to am taking anti-biotics. I took the z-pack and it didn't kick my ear/sinus infection so, I went back to the doc and she gave me Cipro, supposivly a very very strong antibiotic. I was suppose to start my period wednesday. Tuesday night I had cramping and spotting, so I started a new pack of ortho-cyclen. I am just starting b/c again and it seem's that I just skipped my cycle because I did the "day one start" where the insert says to take it on the day you start your period. So my question is does anyone know if starting a pill at the very very beggining of your period cause you to skip your period? I just took a home pregnancy test.. per doctors orders, it was negative. So either it's the antibiotic's I've been on or the fact I just started b/c. hmmm. maybe i should have waited and done the sunday start for peace of mind!