Well done for getting DS out early, essbee! (since there isn't a [proud] one!)
Have you got your bank statements for the year handy? (Or at least would you be able to find them if you looked...mine are in lots of different piles!) Worth checking to see what dates he has paid before; only if soupy is right, and he has changed the date before, he might be diddling you out of a whole month over the year .
If you have DDs set up on the basis of when he pays you then you need to be paid as agreed. Anyway isn't he paid monthly? Why does he need to change the date??? Very fishy.
Hope you have a good day, flower, and that these ADs are the right ones for you