Don't worry. When I did my pre natal, the malay lady also said the same. I was 8 mths pregnant but she said my baby is small like a 7 month old. But gynae said my baby is slightly on the bigger side. My baby came out at a perfectly healthy weight although a preemie due to PPROM.
Only one week? I think there is no risk.. anyway if there is any risk your doctor explain it to you and direct you for the treatment. be positive and don't be stress. God bless to you both.
yes u should. pls follow up closely with gynae