I really wouldnt be concerned, that sounds normal as from what my dr. told me. At 6.4 weeks my baby's heartrate was 107. The baby's heart is just beginning to beat and will speed up in days/weeks to come. I was also told that by the end of week 7 the fetus' hb is normally around 120, that was from the ultrasound technician.
dont stress it to much my babys heart rate at 5 weeks 5 days was 99bpm and now im almost 31 weeks! i know i also had a low projesterone count so maybe u should get that checked! good luck!