13 week checkup

I went to the dr today for a regular monthly checkup. This was the first time I got to hear the baby's heartbeat. The heart rate was 150 bmp. I'm pretty sure when I was pregnant with Alivia, her heartrate was always in the 150's. I did some searching on the internet and found some old wives tales that say if the heartrate is 140 or under it's typically a boy and anything over a 140 is typically a girl. I'm not going to be painting the room pink or anything yet but am wondering if it's another girl. I'm ok with that. It will be a heck of alot cheaper since I already have everything for a girl!!! Rob has been very sure that it's a boy this time, he also has Alivia convinced it's a boy too. I really don't care either way but i'm starting to get the feeling we're having another girl!