In my first pregnancy, I measured about a month ahead for a while. Then, sometime in the third trimester I ended up measuring two weeks behind. Dr sent me for an ultrasound to make sure baby was okay. My daughter was born 41 weeks and five days weighing 7lbs, 5 oz, and in perfect health. So relax. Measuring is not an exact science, just like your baby is going to hit some milestones early and some late. It's an estimate that drs use to mark your progress.
Thank you for the positive feed back!
It happened to me and when they did the ultrasound and it turned out her legs where measuring 2 weeks ahead so she's just super long! The rest of her body was in proportion so I wouldn't worry too much if I were you..good luck!
Your baby might just be bigger or the baby could be lying in a weird position having you measure bigger.