20 week Ultrasound and I am worried!

Ana • Officially PREGNANT With #3!

I got my 20 weeks US last week. I wasn't told anything was wrong but I have a feeling my baby girl doesn't have ears. Every time I see this US pic I freak out. should I be able to see them by now? It was a 3d pic! Should I be freaking out! what's your opinion? any comparisons?