I'm pretty small myself at 8 months and they said my belly was alil small but measure of my baby came out healthy it jus depends on how ur body is I'd u have a long belly or if it's ur first pregnancy but being small has nothing to do with the health of ur baby u could be super small but still have a perfectly healthy baby check with yur doc if ur still worried ND ask for them for a measurement of ur baby to c if his at good size good luck love xoxo