Hello everyone! I'm 35 weeks pregnant and my belly isn't particularly …

Hello everyone! I'm 35 weeks pregnant and my belly isn't particularly big (first-time mom). Recently, I saw my doctor, who says the baby is likely to be small. Although at 30 weeks ultrasound showed the baby's weight matched the due date. And on top of that, my hemoglobin dropped to 108, I tried increasing it with Ferrixil, but it didn't help. There are many scary thoughts in my head. What if the hemoglobin level affects the baby and the small belly too? Has anyone had a small belly and the baby was born not small? How did they increase their hemoglobin?