Answer:
Expericencing the symptoms of a period, such as cramps, bloating, irritability, etc. without the body actually following through with an actual menstrual cycle could indicate a few things. "Missing" periods have several different causes - age, homone levels, stress, malnutrition, menopause, eating disorders, medication, or it could be an early sign of pregnancy. Some diseases and illnesses can also cause irregular menstrual cycles, such as Polycystic Ovarian Syndrome (PCOS), ovarian cysts, Premature Ovarian Failure (POF), ectopic pregnancy, etc. There have also been cases, rarely, of women born without a vaginal tract who experience the symptoms of their menstrual cycles but have no actual cycle as it has no tract in which to travel in.
Most irregular menstrual cycles usually work themselves out, or are treated with the contraceptive pill by GPs.
Do not rely on internet research to diagnose medical issues, always check with a doctor before coming to any conclusions.