No belly at 16 weeks

Is it okay that I haven’t even started showing the slightest yet? I’m 16 weeks & 4 days today & have just been concerned about if my baby is growing correctly. I am a bigger girl so I know it usually takes us a little longer to show but I have a friend who is a week behind me & she’s huge (not sure if it’s the baby honestly) but I just want to be sure. I haven’t had my first ultrasound yet