Maybe you are farther along then you really are. That is usually a hb for weeks 8 or 9. Did they measure and tell you that you were 7 weeks?
I thought there heartbeat was supposed to be fast. I was pregnant 6 years ago, so I do not remember much. I think I remember her having a fast heartbeat though.
sorry i dont know too much about the heart rate and what is normal but i would think that 150 would just mean the baby was really strong and healthy. Did the tech or doctor comment on the rate?