Would that be baby? I thought this young their hb is really fast, around the 150/160/170?
When I was looking into it I found this:
A heartrate around 120/130 with a lot of whooshing is probably not the baby. There's an artery that runs all the way down your belly, and when the doppler is on that artery you hear your heartbeat and also a short noise in between the beats. Not sure if this the sound of a nearby vein carrying the blood back on a brief delay or what, but the doppler picks it up and counts it as a seperate beat. This noise is easy to pick up, and sounds faster than your heartrate, but it's not the baby.
I was looking myself this morning and found the 120/130 one in the middle before I found baby at 168.