Has your babys heart beat been consistant from first Ultrasound to current heart rate (ex. @ 7 weeks was 145, stayed around 145 so far each time)

The first US i had showed heart rate at 170 @ 6.5 weeks so we suspected girl at the time. At 11 week fetal dopler it was 150. At 15 week fetal doppler it jumped around from 145- 180 and then she got it to stay consistant around 145 after changing doppler position. I remember my 3 other kids were fairly consistant throughout so i would like to hear from other mommas. I know each baby is diffrent and each pregnancy varies. Our babies are amazing and i enjoy learning more about them everyday. So mommas,have your babies heart beats been consistant in range or are they all over the charts??