5.5-6wks and low heart rate

Ashley
I just had an ultrasound done today because of cramping and light pink discharge. During the scan we saw the heart beat and she tried to measure it, when she finally got it it was only 77bpm. I am worried because I am constantly cramping but the pinkish discharge stopped right away. I have been super busy cleaning and trying to help paintmy daughters room, so that may be why I had the pink discharge... Idk I'm trying to stay calm but really just scared. Oh and the doctor said although it was low it was a good sign, trying to keep that in mind but terrified because of the cramping. (This is baby #3)