hey.. we bought a doppler at 10 weeks im now almost 13 weeks and we couldnt hear the hb.. we had our scan and everythings ok..so we thought we would listen with the doppler last night and we did.. and heard it!! nice and clear nice and loud..it was so special for it to be jsut me and my husband hearing it for the 1st time on our own! we have the hi bebe bt200 doppler.. and it 2nd hand off ebay and recomend it!