Size of baby?

Megan
I went to my midwife appointment this week at 15 weeks. They have done no ultrasound or measuring and told me my baby is "10oz and 6.5 inches long". I want to believe them but everything app, website and book I have says baby is about 1/3- 1/2 this weight (around 4-5oz) and closer to 4inches. What is right? It concerns me if my midwives were so far off?!