The symptoms you are describing could be early pregnancy or a whacked out cycle this month.
The first thing I would do is take a preg. test. Have you done that yet?
If a pregnancy test comes back negative, I would give it another week or so and see if af (aunt flow) comes. We all have had screwy cycles here and there. If it still hasn't come, time to visit the dr. They can give you something to bring on af if necessary. Good luck!