No. You're counting wrong... your period does not come on the days of the month. Many months have a different number of days than other months. Do you really think your cycle is 31 days long one month and 28 the next, just because the calendar says so?
I definitely wouldn't consider your period late. Give up to a week of wiggle time around your due date.
Go back and count
how many days it has been since your last period.
That's how you count. Go back further if you have good dates, but if you don't, start keeping a log now.
The day of the month is completely irrelevant. My cycles are on average 35-40 days long - I never get one on the same day of the month!