Hi Holly, Welcome to Healthcare Magic Forum. I have gone through your Query & I really appreciate your concern about the problem you are facing. As a physician I would like to tell you that Noriday is a birth control pill commonly known as a progestogen-only pill or mini pill .It causes changes to the mucus of the cervix and the lining of the womb and affects the hormonal control system of the body, which may all contribute to the birth control (contraceptive) action. Due to the amount of hormone present in these pills, your body s hormonal balance changes which leads to Menstrual fluctuations. If you have taken all the tablets correctly, you should not be concerned if you have missed a period. Continue to take your tablets as usual. However, if you have missed two periods, Continue this until your doctor has confirmed that you are not pregnant. It may cause some delays in getting pregnant after you have stopped the medication, but you can get pregnant eventually not to worry about anything. Thanks for Trusting & Posting your Query on this forum. Hope this will help you. Feel free to ask any further question. Have a nice Day. Regards, Dr.Abhijeet