Any one else's baby measuring big??

Melissa • My husband and I were blessed on November 19 2015 with our son Nolan! Currently pregnant with baby #2 👨‍👩‍👧‍👦
I just had my anatomy scan at 18w +2 and we're having a boy 💙💙 but I noticed on the screen he was measuring 6 days a head, i pointed it out to the tech and she said yeah he's measuring a little bigger then I asked if they will be changing my due date and she said no he is probably just have a growth spurt and it should even out. I'm just worried cause I've have 3 ultrasound prior to this all before 13 weeks and I always measured with my due date to my knowledge. Has anyone else experienced this? Could baby be bigger because I'm over weight? This is my
First so everything is freakingg me out :) lol thank you guys!! Btw I've lost weight since finding out I was pregnant 10-15 pounds (dr said it was fine as long as baby was growing👶🏼)