Late Period. Cramps. Negative Test. WTF?

[THE Sam]

Okay,
I've seen some resolved questions about this problem but nothing like mine so here it goes.
I am late for my period and am suffering the same period-like symptoms.
here are the facts:
- My period is over a week late (11-12 days)
- before you start screaming pregnant...i've taken four pregnancy test (one just a few minutes ago) and all have been negative.
-I am feeling cramps. Sometimes they are really bad...like first day of your period bad and sometimes they're light.
-I am suffering from PMS. Seriously! I cried after seeing the New Moon trailer. COME ON! I may be excited but that's a little much!
-I am NOT having unprotected sex!!! My boyfriend and I have had waaaay too many scares in the past. We always use name brand condoms and always make sure they don't break. (yes...we inspect them okay? we're protection nazis!)
-i am REALLY annoyed with this. Sometimes it feels like it's going to start and it just...doesn't.

Can anyone give me some insight?
My bf and I did have sex the week i normally start my period. Did we knock it off? Am I just skipping the month? Someone please!

p.s. SERIOUS ANSWERS ONLY

A little information about me
25 yr old
never been pregnant
usually late on period by maybe a day or so.
longest my period has ever been late was three weeks...but i really don't want to do that again!

Thanks everyone

 

[Peachy :D]

Lots of women are late, sometimes you can even skip a whole month. Don't worry, breath, everything will work out.

 

[confused]

stress can cause you to miss your period, then you're stressing cuz you don't have your period.. its a horrible cycle...it happens to my friend all the time and she flips out and thinks shes pregnant... just calm yourself down and maybe go see your doctor, she'll be able to tell you more.