Not so obvious belly bump

Hi po! FIRST TIME magihing mom, ask ko lang po sana, kasi I am just 23, 13weeks 6days as of today, sabi ng OB ko ang slim ng body ko, and may days may tiny belly bump ko, may days naman na mas obvious yubg bump pag may kinain ako kahit pa konti, worried kasi partner ko and me, is it okay and normal po ba na di kasing laki agad yung tiyan mo ng tiyan ng iba by 13weeks? other friends ko kasi ang bilis lumaki ng belly bumps ???