Two weeks late

My period is two weeks late, negative pregnancy test (we use withdrawal), and i am constantly emotional (always crying), tired and have lost my appetite for food (which never happens to me!!). No sore boobs. Im under a lot of personal stress so don't whether to put it down to stress or something else going on with my body...stress never usually has this effect on me and i always have a regular cycle of about 21/22 days - it's now day 38! 
What do you guys think is going on!?