Hello dear Understand your concern. If you have unprotected sexual intercourse there may be a chance of pregnancy. But it should be confirmed by blood HCG level or by USG of lower abdomen. Other cause may be a side effects of birth control pills. Following are common side effects of pills: Intermenstrual spotting, Nausea, Breast tenderness, Irregular periods, nausea, headaches or weight change, Headache, Malaise, weakness Weight gain, Mood changes due to hormonal imbalance Decreased libido, Vaginal discharge, Visual changes Take tablet meftal saps three times a day for 2-3 days or when pain Take healthy diet with vitamin and mineral supplements Avoid excessive stress, alcohol, salt and caffeine. Do regular exercise. Use safer sex practice and maintain hygiene after and before sex. If persists , you can use other contraceptive methods like condoms Hope this may help you. Best regards Dr. Sagar