Hcg level very low but heartbeat shown

Patient: I had an ultrasound yesterday.embryonic pole and yolk sac identified.crown-rump length 3.6mmcardiac activity at 111bpmsmall area of subchorionic hemmorhage. 0.4x05x0.2cmMy dr dated me at exactly 6 weeks. However my HCG came back at only 1651. Is that number concerning? No cramps or bleeding. I am just very worried but hoping since it seems baby is progressing perfectly it is nothing to worry about.LMP-9/21 1st HCG-10/20-351 2nd HCG 10/22- 654 yesterday 11/5- 1651Is the HCG level being low mean miscarriage or problems with baby? Or is everything okay, as baby measures good?? Please help!

Symptoms: None

Hcg level very low but hear...-1