Small baby

I need help getting my anxiety and obsessing under control! We have been monitoring my BP the whole pregnancy and while it has been slowly climbing, no protein in my urine and it hasn't reached a concerning level. Dr sent me for a growth scan at 36+2 and they saw no need for a repeat scan. They said everything looked good as far as placental blood flow etc and that baby was just small. Fast forward a week and a half to my normal OB appt and my Dr said that baby's head circumference and abdominal circumstance were measuring small and his weight was 5 lbs 7oz estimated so this all out him in the 15th percentile. She told me there was nothing to worry about but of course I got very upset and am thinking the worst and Dr. Google isn't helping. Just wondering if anyone else had similar experiences or advice. Also sick of people telling me I have a small belly!! Thanks in advance :)