So I've been debating for a couple weeks if I should buy a Doppler or not. I had a miscarriage in May and despite many positive appointments I'm still a nervous nelly! I finally gave in and bought one and I am so glad I did! I was able to find the babies heart beat pretty quickly after watching a few videos. It's just so hard to wait 4 weeks between visits! I only plan to use it once a week. So worth $40 for peace of mind...