Baby Gender

Good day po. Currently 16weeks for my 2nd baby. 1st ko is babae and gustong gusto nya talaga magkaroon ng baby brother. Pero wala pa po kaming idea sa gender ng dinadala ko ngayon. So im looking for early signs. Totoo po bang pag below 140 bpm ang heart rate ni baby ay boy at pag higher than 140 is girl? Thank you.