It is not uncommon for there to be a slight discrepancy between the gestational age determined by your last menstrual period (LMP) and the measurements obtained from an ultrasound. Ultrasounds are generally considered more accurate in determining gestational age, as they take into account the size of the baby and various developmental markers. However, there can still be variations due to factors such as individual growth rates or measurement errors. In your case, a difference of a few days is within the range of normal variation. It is important to remember that due dates are estimates, and babies can arrive earlier or later than expected. If you have any concerns about your pregnancy or if there are any significant discrepancies in your measurements, it is always best to consult with your healthcare provider for further evaluation and guidance.