I had unprotected sex (6th nov)on my period and took levonelle the next morning just incase. My period ended two days after and a full period started 5 days after I took the levonelle (3 days after the initial one stopped.) On the 21st the condom failed again and this time I took levonelle within 2 hours of unprotected sex. I took a home pregnancy test yesterday which showed positive. Has the effectiveness been impaired due to the fact that I took 2 course of antibiotics one starting on 10th Nov to treat uti and the other starting on the 25th Nov for tonsilitis?