Pregnancy Due Date Discrepancy: Ultrasound vs. Last Menstrual Period

Question
I just had my second ultrasound,i am in 4th month of my pregnancy.According to ultrasound,my baby growth is more than my completed weeks.My LMP was 14th march 2008.I am confused in which week of pregnancy i am? is it 14th week or according to ultrasound i have completed my 15 weeks according to the baby size.The doctor suggested another ultrasound after two weeks just to make sure the due date and normal baby growth.I need help in this regard.Pls tell me as i got 3 different due dates till the day i started my pregnancy i.e 21st dec,8th december and now she says its 11th of december.

Answer
It sounds like your baby is growing a bit faster than the average- which is perfectly fine and normal! =)  Due dates are based on averages.

I would go with the last estimate given you- that your due date is December 11th and you are 15 weeks pregnant. The further into your pregnancy, the more accurate due dates and the like generally are.

Please let me know if I can help you further or with anything else.

Best wishes,
Helen =)