You should talk to your vet, but to be honest, some vets won't do that anymore. And you have to be careful. I had a Doberman that I got when she was one. Her ears were cropped. Whoever did it, did not do it right and messed her ears up. She cold hold her ears up if she was startled or excited, otherwise, they stayed flopped out to the side, and she looked like Yoda! Not worth it in my opinion.
Never crop any dog's ears. It is cruel, unnecessary and will hurt the dog. Crop your own ears first.