Small baby advice?

FTM and have an appointment with a specialist tomorrow at the hospital to talk about and check baby’s growth. I’ve had a history of very low BMI and have been on injections previously for multiple severe vitamin deficiencies.

Everyone I see constantly tells me how small I am still, that I look more like 3 months then 6.

My midwife didn’t seem to know what was going to be involved in this and couldn’t answer many questions, I can’t find much online so was wondering if anyone else could help me?

I’m getting worried that she’s not going to be big or strong enough and want to be prepared for what might happen tomorrow. Please can someone help?!?!