question about nike plus
 

I started using it on april 1st, so I have been assuming that the big bold red numbers across the top of the home screen, which say 55.98, were my total miles for april (and that they'll keeping going up after april, I'm thinking, all time total?). BUT if I look under activity, it says my miles to date are 59.38. What's going on??? I am about to get out my calculator and add them all up, but it's irritating!