Baby did not grow much

I had my 6 weeks ultrasound where baby had a heartbeat, had another ultrasound at 7 weeks and 5 days and doctor said baby grew 6 weeks 5 days . Baby still had a heartbeat but was faint. I feel like she dint get a good view as it looked totally different from her previous ultrasound. She has called us again to check in few days to see if the view was any better