C.A.
Ok first of all why would you lie? When we found out that I was pregnant my last period was Dec 7, 2010. At that time we thought we were about 11 weeks. When they did the ultrasound it turned out that we were 7 weeks and 3 days. I was very dissapointed about the time frame. The dr's use your last period as a base time and that the ultrasound can only get the extact date. They told us that it all depended on when we actually concieved. It must have been right before my next period cause I never got it. You are only going by the information that you have that is best to your knowledge.
Last year I had a miscarriage at 5 weeks. When I thought that I was 7 weeks I began to have some very light bleeding. We had a ultrasound done and the sac was there but the baby never grew. The sac was empty. I had all the levels there but nothing happened. I knew that something was wrong when the tech kept asking me if I was sure I had the right dates. I didn't have any pain just the light bleeding.
Keeping you in my prayers and I hope that it was just a blip. Take care and Good Luck!!!!