E.T.
I second the idea for charting... cervical fluids can tell you so much.
For getting your period to start sooner... how often are you breastfeeding? Are you co-sleeping? This is not scientific by any means... but my friends and I all breastfeed for quite a while... varied from 13 months - 2 years... for those of us the stopped breastfeeding in the middle of night and stopped co-sleeping... our periods seemed to emerge within a month or two... again, no scientific data... just what our little group saw... we happily breastfed during the day... just not at night... it also seemed to help with the sleeping.