I am currently on trinessa and have been for a couple of years. A few weeks ago I was on flagyl for bacterial vaginosis. I continued to take my birth control throughout at the same time every day and did not miss a pill. 11 days after I was off the antibiotics I did have sexual intercourse. Like I said, I continued to take my birth control as normal, and he withdrew before ejaculating. I also had been off the antibiotic for over a week. I am just concerned on my risk of pregnancy.