Question Title: is it too soon

Dear Katy:
Most antibiotics do not interfere with the effectiveness of birth control pills. Zithromax is not a member of the anti-tuberculous or anti-fungal drugs which are known to increase the breakdown of the pills. Hence, it is unlikely that the TriLevlen would be any less effective on Zithromax.
A urine pregnancy test is reliable 3 days beyond the missed menstrual flow, or 17 days from ovulation. The rules break down in a birth control pill cycle because you cannot know when you ovulated. Thus, the best you can do is test when you have finished the last active pill plus 3 days and if you do not start a menstrual flow by the end of the placebo pills (the last week of different colored pills), see your physician for a blood pregnancy test before starting a new pill package.

Keywords: antibiotics, birth control pills

This information is provided for education purposes only and is not a medical consultation.If you have specific questions, please speak with your physician.