When people say birth control, they normally mean birth control pills, or the Pill. There are many different kinds of birth control pills, although they work on a common premise: the manipulation of the hormones in the female body so that ovulation can be prevented. When taken properly, birth control pills can be up to 99.99 percent effective in preventing pregnancy.
Antibiotics, on the other hand, are meant to kill bacteria in the body; specifically bacteria that causes various illnesses. There are hundreds of different kinds of antibiotics, each differing in strength and formulation.
The idea that antibiotics may interfere with the action of birth control pills and vice versa has been going around for quite sometime. While there is no definitive evidence that supports the interference, there is a possibility that it may occur.
This is due to the effects of certain antibiotics on the liver. When taken, some antibiotics can cause the liver to break down enzymes more aggressively. Estrogen, which birth control pills use to regulate hormone levels in the body, can be broken down. If this happens, ovulation may happen and this can result in unwanted pregnancy.
Again, this is only a mere possibility. You also have to take into consideration that not all antibiotics have this effect on the liver. One thing that you can do is to consult thoroughly with your doctor. If you are taking birth control pills and you get ill, you have to let your doctor know immediately that you are on the pill. He can then determine which kind of antibiotic is safe to take.