Late extent, but impossible to be pregnant?

my periods have been extremely regular since i be 12 (5 years) and i am never more then 1 day late. but its be almost a week since im due and im starting to worry. im a virgin...and i havent fooled around with my boyfriend (activities that involve his bodily fluids) in over 3 weeks...and im positive nought went around my privates because, first it didnt shoot anywhere near and secondly i was wearing pant...
but why am i late?where did my period dance??
Answers:    Don't worry, it's okay. Your periods can get out of funk for several reason. New exercise patterns or stress can change your period. Even a metamorphosis in weight, medications, or an malady can alter your usually regular schedule. The "About" website has a list of 10 reason your period could be late at http://pregnancy.almost.com/od/amipregnan…

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