Hi!
We see a low heart beat like that ALL THE TIME on the very early pregnancies.
Doctors and ultrasound techs often are concerned because we are only very recently beginning to realize that this is a normal heart rate for an extremely early gestation.
Only a few years ago we couldn't see babies that small, so the knowledge is lagging the technology a bit.
If the pregnancy is healthy, (and I bet it is!) the average fetal heart rate will come way up into the 160-180 range within a week or two, and then go back down to around 140.
Best Wishes!
Dr B
Hi there i would not be concerned i had the same thing and around the same rate with my pregnancy and i had a perfect little boy the heart rate has prob just started and it takes a few days to a week to speed up! i was really concerned when the told me its only natural to worry!
Congratulations i am sure everything will be fine
Ally