Hello, Thanks for writing to us. Irregular intake of birth control pill may lead to hormonal imbalance and late period. You should be regular on pill. Do one home pregnancy test to rule out pregnancy at the earliest. In absence of pregnancy, other reasons of late period may be due to PCOD, ovarian cyst, hypothyroid state, over weight/ extreme loss, extra mental stress or anxiety, emotional upset, eating disorder, high prolactin. Here, I suggest you to undergo complete hormone profile (LH/ FSH, serum prolactin, progesterone, thyroid, DHEAS, testosterone etc) and pelvic ultrasound scan. Review with test results or you can consult with local gynecologist. You may require hormonal pill to induce period. Maintain genital hygiene, control body weight. Good luck.