First: the volume of your menstruation is pretty much set before you start menstruating. So, I doubt it - you probably just ended up having it be a little lighter when it would have been at it's heaviest. But yeah - sometimes the period and the first new pills overlap for me. Won't hurt ya.

Second: It doesn't stop, usually, but it often slows down. I think it either has something to with osmotic pressure and your body's natural defense against foriegn stuff getting into your vagina and the fact that we expect a heck of a lot more to show up because out of water it collects but in water it disappates as soon as it gets outside your vagina.