Nervous about anatomy scan

I’m 17w4d and have my anatomy scan in two weeks. Very nervous about it. I’ve had two losses previously and I’ll be 40 at the time of delivery in August. I know it should be an exciting scan but they will also measure everything and I’m afraid they’ll find something terribly wrong. Anyone have any success stories even being older? I’m wondering what the statistics are of something being wrong at the 20 week scan.