Baby 15th week scan

Hi Mummies. Has anyone gone through their 15th week scan where they measure baby head size? Was told that my baby head size is in 5% while normal size is 10% and above. Was wondering what about other babies or does anyone experience their baby having small head size? Was told not to worry, and that it will be monitored at the next scan, hopefully it's not a case of microcephaly. But being human, I can't help but to worry and keep thinking that I could have provided better nutrients to help baby's growth 😞