30 weeks and scared

I need some reassurance please. I'm 30 weeks now and have been having reduced movement for 5 days. I've been to the hospital twice and they do a CTG and the baby's heart is beating strongly but there's still a considerable difference in the movement I was having last week and for the last six weeks or so. They measured the baby yesterday and he/she is measuring small, in the 20th centile. They didn't explain to me what this could mean as I am seeing my consultant tomorrow anyway so they wanted to do more in depth scans tomorrow. I'm so scared. I'm doubting movements, I'm nervous and trying to hold it together but I'm struggling to. My mum is the only one who knows how scared I am because my husband is very nervous about it all too and on top of that is worried out of his wits for me as I'm exhausted, can't get out of bed and go to work exhausted so I'm being investigated for anaemia. I just need some reassurance that I'm doing the right thing in trusting the doctors