Whay are the chances of getting pregnant while on birth control and missing a pill while taking antibiotics?

1 pill not likely: Missing 1 pill is not likely to increase risk of pregnancy by much, there's more risk if the missed pill extends the hormone free days>7 d. Antibiotics also aren't likely to cause the pill to fail. However, some women may be at higher risk for failure from either missed pills or antibiotics than others. Try not to miss pills, and to be safer, use a back-up such as condoms during antibiotics.