Nope, that's why they call it a grace period. Grace is the gift of time to pay.
Most mortgages have payments due on the first day of the month with a 15 day grace period. That means as long as they receive your payment by the fifteenth, it's considered on-time. Any payment received by the lender after the end of the grace period is late and will affect your credit record.
If you are not sure about the due date and grace period for your mortgage, you can find the terms in the NOTE signed at closing.