I have a question about home fetal dopplers, more specifically, Sonoline B fetal doppler.  

I purchased it because I had a miscarriage last year, and am now 14 weeks, 5 days pregnant, and want to hear my baby's heartbeat in between my appointments.  I read online that it is essentially safe, but at my 13 week ultrasound appointment, the technician advised me against using it, as its not safe for the baby!  I had only used it approximately 6 times since getting it at 9 weeks, and would like to know if anyone has one, and if they were advised not to use it.

Any feedback would be greatly appreciated!