Baby at lower percentile

Mummies who gave birth to their baby full term and their baby now still at the lower percentile, did your baby turned out fine when they grow up? My 4 months old is only 6.3kg and 60cm and its small for his age and im very worried. He used to be 6.6kg but got sick and lost weight. He looks small physically. Sometimes i cant help but to compare him with other babies esp those in his ifc and same age. Altho i know we should not compare our baby. Can i just know how much your baby weight and their height at 4 months?