Birth Control interactions with Oracea(doxycycline)

Patient: If I am taking 40 mg of Oracea once a day for an extended period of time to help with acne, will my birth control (the pill) be less effective/ineffective, or does the fact that I have been taking Oracea for a couple months not have an effect on the birth control. I was also wondering if because it was a low dose if this would make birth control more effective than if I was taking Oracea in a larger dose?

Symptoms: None