When I went for the dr yesterday, I was measuring 35 weeks; however, the baby is measuring about 30 weeks and 4 days according to the ultrasound. I asked the dr if measuring big was a concern, and he said no. It looked like i just have more amniotic fluid, so he said things were fine. I hope this helps.
I have a similar situation- I'm 31 weeks, but at my last appointment I was 29 weeks measuring 33. I have an u/s today, so I'll post later and let you know. I would love to have this one early, but we'll see what happens.
If the measurement was for fundal height, I wouldn't worry too much about it as that's not always very accurate. If you're measuring that much more advanced on ultrasound, then there is a possibility that you'll be having a larger baby. And even the ultrasounds can be off by quite a bit as Zazou mentioned. Something to ask at your next appt would be whether they think your baby's lungs have developed at that same rate because unfortunately that isn't always the case. I wish you the best of luck and hope to hear good news soon! :)
My little one was also measuring 3 weeks ahead at 28 weeks and then at the 31 week visit she was measuring 7-10 days ahead. I was told that ultrasounds in the third trimester are not so accurate. Many of my friends who have children have told me how inaccurate the 'estimates' were e.g. one friend was told her daughter was too small, she came out 53 cm, and another friend was told her daughter would be 3.5 kg, she came out 3 kg (and this ultrasound was conducted the DAY BEFORE she had her c-section). I wouldn't worry too much about it.