Babys heartrate low HELP

So I had my first ultrasound last week at 6w1d. The baby's heart rate was 95 and while the doctor said its low the tech said as long as it is between 80-180 its normal. The doctor had asked me if I was having any bleeding (which I haven't been, I've has two miscarriages so I know what to look for) because the heart rate could be indicative of something or be just contributed to the fact I was at the point where the baby's heart had just formed. But she's going to do a repeat ultrasound Wednesday to check then, when I will have just turned 7weeks. Anyone else have this happen? She told me not to worry and she wasn't my actual doctor after all but a nurse midwife student I'm conflicted with believing Her instead of the tech who's been in Her profession awhile. Please help I'm so worried!