Did anyone else have a baby on a low centile?

My son is 3 1/2 months and has been consistently following the 9th centile for weight and 25th for height.

Did anyone else’s baby start on a low centile but end up catching up?

My husband and I are both average height and slim. I don’t understand why he isn’t very long if we’re both average? I think his low weight is very much a genetic thing since we’re both naturally that way too.