Im worried somethings wrong with my unborn baby ..?

im 34 weeks and mesuring 3cm down. i have a very small bump too and my baby is healthy. he is a timy bit on the small side but hes still healthy. my belly really started to pop at 32 weeks. so give it time. its just the way you are carrying the baby :) if you are really worried then go for a ultrasound to check the sizee of the baby. good luck and congrats