Every Month My Period Come After 28 Day's So This

every month my period come after 28 day's

so this month my period date is 23.8.15 , so I take primolut n from 19.08.15 because have some function in my home ( I planning to 10 day's take)

but I want to one information
in next month my period come same as before after 28 day's

or any change ?

pls give me the advice for next month period come same 23. 08.15