I haven't had my period for more than 40 days.

Menstruation cycle is in normal control in 28-30 days, more than 40 days did not come menstruation, should consider whether to be oneself endocrine disorder is caused. If sexual life exists recently, should consider whether to be pregnant the menopause that causes. Suggest you go to hospital department of gynaecology to see a doctor, find out the cause symptomatic treatment.