Fetus Height and Weight

Hello, first time mom here. 21 weeks 6 days na po ako, pero last month my baby was 5cm smaller than the usual height. If I were to follow this app, 26cm na po dapat sya, but she’s only 18.9cm palang. Is this something I should be worried about? Sabi naman ng OB and midwife na pinag pacheck upan ko okay lang naman daw. Baby is healthy, since completo naman ako ng vitamins, milk, and kain. Worried lang ako, may naka experience na rin po ba neto?#firstbaby #advicepls #pregnancy