I have all my period symptoms but no bleeding?

I believe i was supposed to start my period about 3 days ago. I was having my usual period symptoms like sore breasts and stomach cramps, headaches. I heard that stress can be a factor in missed periods, Im hoping that is the case because this month has been definatly the most stressful that I have had in years. My concern is i've never really had a period this late before, Is stress the cause or what should I do?