First Pregnancy Concerns: Early Ultrasound Findings & Next Steps

Question
I'm 28yrs and this is my first pregnancy, my last period was 11-29-05. my cycle is btw 32-35days.I've had 2 preg. test and shows positive. i've never had any serious symptoms except my breast getting bigger. i had my first ob visit and she sent me for blood work and also early OB ultrasound. my sonogram was yesterday and the technician couln't see a fetus so she called my doctor for a transviginal. finally she was able to see a fetus, but saying it was too small also she said she detected a heart beat but wasn't saying much. Also she said what the ultrasound is calculating is i'm like 6wks and 3days. could she be right and from my calculation i should be around seven wks or thereabout same thing thing my doc said on my first visit. and my next appt. is 4wks away . should i be worried  

Answer
A sonogram at 6-7 weeks gestation (from the first day of your last period) is very innacurate in determining gestational age. I would suggest that you repeat the sonogram at 20 weeks, when it is much more accurate in confirming your gestational age. If the sonogram only showed 6 weeks 3 days and you think it should be 7 weeks, it is only 4 days off. Don't worry.