Measuring ahead

Tonya

Hey I'm 26 weeks 3 days pregnant today and just left an prenatal appointment my doctor has confirmed that doctor is measuring 4 weeks ahead at 30 weeks instead of 26 weeks . Has anyone had this happen and their due date change? , or will baby just be big at birth. My other two measured normal my first born was 5lbs 8oz at birth but was born 2 weeks early and my second born was 7lbs 11.6 oz at birth and was born 4 days late