Fundal height

Both times my doctor has measured me i was measuring 7 and 6 weeks ahead, doesnt that seem like a lot?! She hasn't said anything about it and it has me worried. Ive tried asking for another ultrasound but she wont since baby only measured 4 days ahead at 19 week ultrasound. Not to mention a friend of mine is pregnant as well measured only 4 weeks ahead and she gave her another ultrasound! Has anyone else measured this much ahead?