I'm not a doctor, but you only have to ask on a parenting forum or Facebook page or other mums IRL to find out these scans are often inaccurate. In fact I would create a post on here and ask because you might find it reassuring.
There's also nothing wrong with being on the 10th percentile, someone has to be one end and someone the other. We're all different. Also think about what kind of build you and your partner are, I've met women who have a lower percentile baby but both the parents are quite small so.. it kind of makes sense? Small doesn't mean unhealthy.
I don't know what the consultant will say, but honestly it sounds like they are just being cautious. You've ticked a box so they've organised a consultation.
My trust tried to organise me a consultation because my iron is a bit low, even though both my midwives agreed it was unnecessary as my iron is not low enough for a transfusion so there isn't even much they can do.
If I were you, I would call or message my midwife, tell her you're feeling worried and what does she think will be discussed with the consultant, she will know their procedure's and hopefully you will be reassured.