I'm having a boy and his heartbeat was always that high. Heart rate has nothing to do with gender
My son and daughter were the same lol. Best bet is by ovulation date vs when you actually had sex. Sex one day before on or after ovulation boy and sex 2 days or more before ovulation girl.
Heart rate has nothing to do with gender my daughter was always 168 and my angel baby was a girl as well and always a flat 140