 [ Symptoms ] no period in 12 years  i am a 27 year old woman i smoke a pack a day i have not had my period in 12 years and i do not know why i have never been pregagant i am not on birth control [ Disease ] you should definatly go to a doctor about that 12 years is a very long time if you are smoking a pack a day that could be a huge reason why go to the doctor for sure