Hello, Yamini is combined OCP and very much effective in prevention of unwanted pregnancy. Though it has failure rate of less than 0.5%. She is probably pregnant due to failure of the pill. Here, she can continue the pregnancy after undergoing one vaginal ultrasound scan to check gestational sac properly along with fetal cardiac activity around 5-6 weeks. In general, hormonal medication does not cause as such ill effect to growing embryo before 4-5 weeks. She should discontinue the birth control pill. Otherwise, she can opt for abortion medically or surgically (D & C) to avoid this pregnancy after consultation with her gynecologist. Good luck.