Hi my baby is 12 weeks and I was wondering why my obgyn said I was pregnant in August 21st 2013 when I am 12 weeks as of today February 7 2013

You mean due on August 21, 2013?
Your conception date is calculated by the first day of your last period. Once you get further along, they might go by the size of the baby rather than your period date.

You mean due on August 21, 2013?
Your conception date is calculated by the first day of your last period. Once you get further along, they might go by the size of the baby rather than your period date.

OK I am not due on August 21 she said I got pregnant on August 21 2012 and I am three weeks and I was on because and never gotten my period I was worried why she said that I was pregnant on August 21 when my baby is three months she speicfally said I was pregnant on August 21 does that mean it takes three months tor the egg to even come out of the fallopiean tubes and then form after 3 months cause this is my first time

Can someone please answer?

Wait! Please back up the bus.

You think --

Conception date:

Due date:
~~~~~~~~~~
Doctor thinks --

Conception date:

Due date:

If you didn't have a period, there's no way for us to tell you when you conceived. Even if you had menstruated regularly, it would still be a best guess, and a best guess can be off by up to a month, even more depending on the person.

The doctor is likely going by an ultrasound. An ultrasound is also a best guess, but can be a bit more reliable than your last menstrual cycle. The doctor is likely judging your due date by the size of the fetus, your measurements, etc. But, even with an ultrasound there is no way that the doctor can give you an exact date for when you conceived.

If this is a matter of paternity then the only thing you can do is wait for the baby to be born and get a DNA test.