Baby weight? Is my baby really small?

I’ve read and read and my baby seems to be measuring right, but my doctor told me he was measuring small and wanted to do another ultrasound.

At 14 weeks he was 3 oz- I’ve read 1.5oz is generally it.

At 18 weeks he was 7 almost 8 oz- I’ve read 7.5oz is generally normal.

She said he’s in the 9th percentile and made me a little worried. His heartbeat has been steady, and he kicks like crazy.

Any other moms? Does this sound normal or is he small?