I want a Doppler but.....

I really want to purchase a Doppler right now cause I actually have the money for it right now. Its to early for me to be able to hear anything of course so I'm wanting it for later in about two weeks. But I'm afraid that I will buy it and then go to the Dr and find that there's no viable baby since I have yet to do my dating scan which isn't till the 7th of sep. I'm scared I'll buy it for nothing and it will just serve as a painful reminder or something. I dunno what I should do, I know I'm weird. Anyone have any advice for me here. Should I just wait?