Always check your next statement
Your statement only shows the balance on your card up to the date it was issued. Even if you do not spend any more on the card after the statement issue date, interest may still be accruing on your balance.
That's why it's really important to check your next statement after you have paid off the full balance indicated on your statement. There may be interest or additional spending from the days after your statement was issued, that will still need to be paid off.