if i'm not mistaken the mayo clinic studied this and said only one anti biotic has been shown to impact birth control's effectiveness at all. it's "rifampin". out of an abundance of caution some doctors suggest using a second form of birth control for a month. i'm not sure how much it's affecting your life now or how much an unwanted pregnancy would mess things up. i never bothered with an extra form of birth control b/c of anti biotics but surely one month of a back up won't hurt.
when can i have unprotected sex with my new husband after taking antibiotics? . after being on birthcontrol for years i recently went on sulfameth/trimethoprim 800 i took 2 pills twice a day for 7 days. the day i started my antibiotics was the same day i started my placebo pills which i started my period four days later as usual. on the last day of my antibiotics i started my new pack of birth control as prescribed (gildess fe 1. 5/30). i am curious when my husband and i can have unprotected sex with no concerns of getting pregnant. help we are newlyweds!