Unexpected...

[eveglass]

I thought the whole point of taking the pill is that it made your periods really regular. And I thought the point of starting on a Sunday was that your period would start on the Monday. At least, that's been my experience for the last two months, since I started taking it. So why, oh why, did my period start today? Is it just one of those "still getting into the system" things, or is it not as regular as I thought it would be, or what? I've taken all the pills on time, so it wouldn't have anything to do with missing.

Anyone on the pill (or in med school) who can help me out with this one?