When on the pill (taking it daily), what is the likelyhood of getting pregnant the last day of or, the day after your period?

Very unlikely, although the chances will be different for everyone.  The pill is designed to stop your system from releasing an egg at all.  In order for you to get pregnant while on the pill the pill will have to not work.  It is not certain that you will get pregnant each time you have sex without protection from pregnancy.  Again these odds are different for everyone.   The odds are slightly less if you have sex during your period, you can read about that in this question.