30 weeks but measuring small

So I had my 30 weeks appointment today. Heart beat is 147 so that's good. I'm 30 weeks and 1 day but they said he is measuring tiny at 27 weeks 2 pounds 9 oz. so I went to a specialist so they can do better measurements which they came up with 28 and 1/2 weeks 2 pouns 12 oz. instead which is still really tiny... they also did a biophysical profile on him this morning and he scored a 8/8 so that's good. I'll get another ultrasound in 2 weeks to check to see if he has gained any more weight and they will go from there to determine what to do. I'm freaking out cause I'm scared to have him early and potentially have to have a c-section. Has anyone else gone through this?