My baby grew less than 0.10 cm in 10 days :(

I went in for my 8 week scan and felt so upset that my baby’s size was only 0.65 cm and measured 6 weeks 4 days. I expected it to be about 1.50 cm long.

10 days ago, I had a scan done at a different clinic and it measured 0.57 cm (6 weeks 1 day). It has grown less than 0.10 cm since last ultrasound. I feel so worried, although the baby’s heartbeat was quite strong, 140bmp. Could it be a technical error? I hope they’re wrong. Should I have another scan done at another clinic? :(