There are several possible reasons why your gestational age may be ahead by two weeks compared to your last menstrual period (LMP). Firstly, it's important to note that the calculation of gestational age is based on the assumption of a regular menstrual cycle of around four weeks. However, not all women have a predictable cycle length.
One possible explanation could be that you ovulated earlier than expected in your cycle. Ovulation typically occurs around two weeks after the start of your menstrual period. If you ovulated earlier than usual and conceived shortly after having intercourse on November 28th, it could account for the discrepancy in gestational age.
Another possibility is that there may have been an error in dating during the ultrasound scan. Ultrasound measurements can sometimes vary slightly depending on factors such as fetal position or technician experience. It's also worth noting that early ultrasounds are generally considered more accurate for determining gestational age compared to later scans.
Additionally, it's important to consider the potential margin of error in estimating gestational age based solely on LMP. This method assumes that fertilization occurred exactly two weeks after the start of your last period and doesn't take into account individual variations in conception timing.
If you're concerned about the difference in gestational age between LMP and ultrasound measurements, it's best to discuss this with your healthcare provider. They can provide further insight based on your specific circumstances and may recommend additional tests or evaluations if necessary.