Baby size during first trimester

Hi mommies, I’m a little anxious and I’m hoping to get some assurance here 🙏🏻 I’m currently 8 weeks pregnant. More specifically when I went for my US last Friday, I was 8 weeks 1 day. Today the baby measures 8 weeks 3 days instead of 8 weeks 5 days. I’m worried that the baby isn’t growing as well as she should. Does anyone has any experience with this ? Is it because I am not eating enough for baby to grow? Also to share - I’ve had 2 MC in the past 6 months so anything abnormal now is making me very very anxious … 😥