My midwife got this wrong. Said it was a horse when it turned out to be a train Also the prodding around just before you listen to it can make the heart rate increase (girls' heart rate is usually faster)
My midwife said ds sounded 'like a train' and therefore must be a boy. However, she did say not to buy blue just yet as she might be wrong. My sils parents were told she was a boy from her heartbeat and they bought blue EVERYTHING, oops!