simple maths eludes me

(and to the giant bunch of weirdos who just yelled at their screens, "it's math. MATH!!": it's NOT, because don't call say mathematiC, do we? Now go correct your bunch of weirdo friends)

Okay, so they're just boobs and there is that thing called PMS that generally inflates your hooters to LongLowWhistle proportions anyway. Check on that.

But they still hurt and are kind of hot and also lumpy. SO SEXY.

Anyway, the mathS question is this, because somehow I missed out of fully understanding exactly WHEN your period is due: when is my period due?

Let's assume a standard, tickety boo twenty eight day cycle. (which mine was this time, HOW CONVENIENT)

If day 14 was on the seventeenth of this month, day 21 was LAST Friday, and day 28 was yesterday, when is you period due? Today? Or yesterday?