Due date change? Confused


So I’m a little confused! I had my anatomy scan today and everything is looking great! But instead of my due date being March 5, they said he’s measuring 5 days ahead so Feb 28. But they are keeping my due date March 5. Anyone have an idea why? It’s only a 5 days difference I know... but I wanna know what I should put on all my apps to give me the correct growth updates lol I look forward to each week!