Worried about my baby girl

So I went for my growth scan yesterday and the women who did my scan said my baby girl is still small she's not grown im doing everything right I look after myself im eating I don't know what's wrong with my little girl when I went for my first scan on the 8th of June she wasn't growing im really worried now they have said its urgent cause a doctor is going to ring me to for a scan to see what's wrong my first pregnancy wasn't like this my first daughter was growing and she was born at a healthy weight im just waiting for the doctor to ring me im so scared she might be born premeture I hope not I want her to grow big and strong and be born at a healthy weight 😞😭