What Causes Missed Periods While Sexually Inactive?

Hi doctor, i have a problem because i labia minora itches everytym before i get my period and i also get what seens to be folliculitis. I have missed my periods for two months but im not pregnant nor sexually active. The nurse said its probably a hormonal imbalance but I should visit the doctor, haven t had time but what do you think it is? Do you think its something to be worried much about?