Anatomy scan at 19 weeks - Too early??

Hi all! I've been scheduled for my anatomy scan when I'll be 19 weeks and 2 days. I was given two options for my scan - either 19 weeks or 20 weeks.

My husband will be away for business during weeks 20 and 21, so it seems like 19w is our only option.

I had asked about 22 weeks and they told me that would be too late. I guess they check for abnormalities and defects, and 22 weeks wouldn't give them enough time to do what they need to do??? I've never heard of this before. Anyone else been told this?

I guess I'm just wondering if 19 weeks is too early. I've heard of people needing to come back for additional ultrasounds because the techs weren't able to get good measurements at 19 weeks. Has anyone else experienced this? Do you think 19 weeks is too early?