I was on antibiotics for tooth pain and was taking my birth control and had my period and i finished the antibiotics but i'm still on my period why?

Antibiotics: Antibiotics can interfere with birth control medicines. Be sure to use other protection when taking these. See your gynecologist for evaluation and recommendations.

Interferences: Some antibiotics can interfere with the hormones in the birth control pills, you need to contact your ob-gyn to see if the issue is related. Alternate birth control is recommended when on some antibiotics.