Hi chick86,
well, it really might not be what you think. First, take a home pregnancy test to see if you're pregnant to begin with. Second, if you're not pregnant, it's probably your pms symptoms, since your period was pretty late (i have really bad pms sometimes...The same things you described). You might have been stressing over something, wich screwed up your cycle. If you changed your diet, it might have been responsable for that too. Also, if you are worrying about being pregnant and you're sure that what you have are symptoms of preg., it might just be all in your head... I've had that not too long ago. You haven't indicated if you've had a positive hpt, so, I would recommend that you go to the pharmacy and get one. They usually come in packs of 2, so if you do it, and it's negative, and you're still not sure, you can do the second one a couple days later to get a better reading.
Well, good luck :d
joem112630