Old wives tales

My babies heart rate at 12 weeks was 140, I just used a at home Doppler 4 days later and the heart rate is still around like 138ish. Did anyone have a heart rate of 140 or below and still had a girl? I honestly don’t mind having either gender, but everyone keeps telling me, due to the old wives tale.. its a boy. I sort of just want to prove them wrong because of the fact they are using that to tell me my gender.. lol