Is ampicillin bad to take while on lessina birth control pill?

Neither good nor bad: Ampicillin is a penicillin-type of antibiotic (antibacterial) used to treat some types of bacterial infections. Generally, if a person can take penicillin-type of antibiotics without problems, then she can take them with or without birth control pills. The current thought is that commonly used antibiotics like ampicillin do not noticeably affect the effectiveness of birth control pills.

Should be OK: Antibiotic interference with hormonal contraception, especially low dose pills, isn't quite an urban myth, but it comes close. The risk si theoretical with extremely few failures. To be safest, check with the doctor or clinic where your pill was prescribed, but this really isn't anything to worry about.