confused about how many weeks pregnant i am

[arisol02]

Hi I'm 13 weeks pregnant but my doctor said that I'm 15 because that's what the first ultrasound showed. Other ultrasounds show I'm 13 weeks.that also the time since my last period  The doctor says the first ultrasound is the one that matters. Am I relly 15 weeks ??  Help please

[arisol02]

Thanks everyone for your comments. If I'm not mistaken I was 5 weeks but according to ultrasound I was almost 8. I'm having another ultrasound on the 1st hopefully they tell if its a boy or a girl  

[yelloweskimo]

The earlier the ultrasound is done the more accurately they can predict how far along you are. Babies grow at a very similar rate at first and then they start to differ and it becomes difficult to determine how far along someone is. When was your first ultrasound done? How far along were you then?

[durhamjk1]

Baby's grow at different rates and each pregnancy is different - they are actually only estimating how far along you are and thus your estimated due date.  They were off with my little one by up to two weeks (he stayed in two weeks longer) and at the last ultrasound - they adjusted my due date (at 30 weeks) to two weeks later.  Also keep in mind that the gestational age is always off by 2 weeks (doctors count the two weeks prior to conception as weeks one and two) so you may want to check that!