Heartbeat old wives tale...!!

Ok so my mom is totally convinced we are having a girl just because of the fast heartbeat our baby has! The first ultrasound I was 9 weeks and it was 180ish. Then at 11 weeks it was 170ish. How many of you believe in this old wives tale! I don't find out for another 5 weeks and I'm actually finding it quite humorous how strong my mom thinks it's a girl! Would love to hear some stories! 💙💕 and btw--- team pink or blue hubs and I don't care! We are over the moon excited for our bundle of joy.