For everyone wondering about the distance, if it's more on your own GPS, it just means you weren’t cutting corners— literally.
For a USATF-certified course the distance is defined by the shortest possible route a runner could take without being disqualified.
For most races, a certified measurer rides the course on a bike, staying near the curb and taking every available tangent. This ensures that all runners will run at least the declared race distance and very few will actually run just the exact race distance because most people won't take the angles and hug the curb the whole time and people have to take extra steps around others participants, hit a water stop or stay to the middle or outside lane.