Don't worry. Fetal heart rate varies a lot during the day, esp so early in pregnancy. It is the average that matters. At this stage of your pregnancy, you can just relax and follow the advice of your OB. Depending upon if any high risk factors have been identified for any action to be taken to prevent loss.
Normal fetal heart. Starting at week 5 the fetal heart will accelerate at a rate of 3.3 beats per day for the next month. The fetal heart begins to beat at approximately the same rate as the mothers, which is 80 to 85 bpm. Below illustrates the approximate fetal heart rate for weeks 5 to 9, assuming a starting rate of 80 Week 5 starts at 80 and ends at 103 bpm Week 6 starts at 103 and ends at 126 bpm Week 7 starts at 126 and ends at 149 bpm Week 8 starts at 149 and ends at 172 bpm At week 9 the fetal heartbeat tends to beat within a range of 155 to 195 bpm. The fetal heart rate will begin to decrease and generally will fall within the range of 120 to 160 bpm by week 12.