Hi and welcome to HCM, The post coital bleeding is most commonly caused by lesions of the cervix. Most common are cervical erosion [infection or inflammation of the cervix], cervical polyps [non cancerous tumors of cervix, cervical cancer [rare at your age]. All of these are diagnosed by visual examination of the cervix by a doctor. So it is important that you get yourself examined. Also get a pap smear test done to rule out any abnormalities of cervix. An ultrasound will help as sometimes bleeding during sex is only incidental and the cause lies in the uterus like fibroids. Headache may be due to many reasons. Pill withdrawl rarely causes headaches. Please check to see if you have any disturbances in eyesight, increased stress, also get a blood pressure check as these are common causes of headaches. A physician will be able to help you with this one. Regular exercise and proper diet with plenty of fruits, low sugars and salt help restore the hormonal mileu. Hope this was helpful. Thanks for using HCM. Feel free to ask any more queries and I am here to help you. Have a good day. Dr Madhuri Bagde Consultant Obstetrician and Gynecologist