If you have been taking your birth control pills as directed, have not missed any pills or taken them late, and as long as the sexual intercourse occurred at least one week after you finished your antibiotic treatment, pregnancy is highly unlikely. Illness and use of certain medications can cause menstrual irregularities (including a missed or late period). Since you did miss a period though, take a pregnancy test just to be on the safe side.
9. January 2012
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