Anatomy scan results??

Amberlee

So I had my anatomy scan done today and it literally took like 15 min ..... I’m currently at 19 weeks and he was measuring 18 wks 4 days the ultrasound tech knows me really well and has know my whole family for 25+ years and said he looked great..... is this normal? Most people’s scans take 45 min to an hour is what I have heard.... and him measuring a little behind has me concerned 😟