Fetal Doppler

Raven • 21, happily engaged and expecting our little rainbow child!
I have a Sonoline B Fetal Doppler, 3mhz, and I've been using it more than I've wanted to. 
I was wondering if there were any mothers out there who have consistently used a fetal Doppler throughout their pregnancy and had a healthy little baby born!
I'm such a nut about it and I always tell myself I'll stop using it for a long time, but after a miscarriage four weeks before I got pregnant with this little rainbow baby, I get easily freaked out!