Heart beat gender theory...

MomOf2 • Married 💏 DD:4yrs old 👑 Angel Baby 5/6/2014 👼 My Rainbow Baby! 5/21/2015 👶🍼💙
So at 6weeks 1 day my little beans heart beat was 120bpm, now at 10 weeks 2 days the heart beat was around 160 beats per minute. The reason she said that was because she used the Doppler - so I don't know if they know the exact beats? 
Anyways, where does that leave me? 
Girl? 
Thanks! :)