Hi, and thanks for your medical question on eHealth forum!
If you have not had your periods for 2 months, and previous to that had regular periods then you could be pregnant as you also seem to have other associated symptoms such as food craving, more sleeping etc. Pregnancy tests can be false negative or be negative if you tested early. Hence repeat a blood pregnancy test and confirm.
If it is still negative then other causes of delayed periods will have to be looked into. Thyroid problems and abnormal levels of FSH, LH, prolactin, androgen hormones or male hormones and estrogen hormones too can be the cause. MRI of brain may be required to rule out pituitary tumors secreting prolactin. Another major contributor is polycystic ovarian syndrome (PCOS). This can be diagnosed by a CT scan or abdominal ultrasound and tests for insulin resistance.
Smoking is also often associated with secondary amenorrhea and can be worse in presence of stress. Sometimes tumors of the ovaries and brain may also cause absence of menstruation. Severe anemia and malnutrition, excess weight gain or weight loss too can contribute.
However, it is very difficult to diagnose and treat your case on net or offer any further advice. Please consult your gynecologist. Hope this helps. Take care!