fetal doppler

Did anyone buy their own fetal doppler? I bought one but emailed my doctor and she said they recommend against them due to "safety reasons". I didn't get to ask anything else. I'm 6 weeks 5 days so I know I wouldn't hear anything yet but I don't have my first apt even talking until around 8 1/2- 9 weeks. The company says they are FDA approved and Canada doctors use the brand. It's sonoline B or something like that. If anyone has any experiences of their own that would be great!