Taking Anibiotics and Birth Control Pills at Same Time

The current practice recommendation is that most antibiotics do not affect birth control pills. The exceptions are isonizid (used for TB) and one other that I can't remember off the top of my head. As a rule of thumb, if you do not experience any diarrhea or vomitting due to your antibiotic then you are probably safe as far as protection. Check out your birth control company's website for the latest on this because it is new information but you probably don't need to worry.

I believe most antibiotics stay in your body for several days after you stop taking them, so the decreased effectiveness of the pill could last longer than you think. All that aside, if you got your period 2 days after having unprotected sex, I would venture a guess that you were well past your ovulation date & it's very unlikely you're pregnant. However, if you're very irregular or if you had unprotected sex a couple weeks b/4 your period, I think you could be pregnant. If you got your normal period you're probably safe, but then again I had a friend who had a "period" each mo. for the 1st 4 mo. of pregnancy (but this ran in her family).

Okay so you got your period while on the antibiotics right? But finished them before your period ended. I would say you are safe. I always understood it as while on antibiotics your birth control is affected. Once you are done with your antibiotics they are no longer present in your body (24 hours after the last dose)so your birth control is no longer affected.

I would say check what your instructions on your pills say. I know that if you take the antibiotics you have to use back up for the entire length of the course of antibiotics. Then as you continue your birth control pills it would almost be like you had skipped the pill. SO for example you stop taking your antibiotics on a Friday, my pills say, if you forgot to take a pill, then you must use back up for atleast 48hours after missing that pill. That would mean on my pill I could be safe as soon as that Monday. Did that make sense? But I know different pills say like 7 days if there is a missed pill so check your instructions or call your OB office and ask. If you are worried go buy a pregnancy test.

Anne,
I asked my Dr this exact question. I have two great kids but we're done so I am extremely careful. He said that it was a good question and that unfortunately he wasn't aware of any studies on it. To be safe, he said to use protection for the rest of your cycle. Since you've had a period, odds are you're okay.
Good luck!
Lacylyn