Drop in heart beat 7 weeks

[Mhmb]

I went in for an ultrasound and was told I was 5 weeks 5 days and baby looked good with 110 bpm. Went in at 7 w 3 days baby looks good but heart beat dropped to 76 bpm. Doctor said most likely end in a miscarriage. This is so hard cause baby looks healthy and I have all the symptoms. This is 5 pregnancy. Son who is 5 and the been trying for 4 years with 3 miscarriages to have another kid. Anyone experience something similar? Would love to hear from others good or bad.