NHS -Who do I call before 8 weeks???

Ru
I've been having some worrying symptoms and I'm totally lost as to who to ask for help. I know if I go to A&E they will just check for ectopic then send me away and maybe book me for a scan on another day (this happened with my m/c in Feb). I've had peachy/yellow discharge yesterday then watery cm that is yellow today with severe back ache. Back ache feels like what it did when I started miscarrying last time. I am beyond worried and heartbroken that I could be miscarrying again. I just want some advice and maybe to be booked for a scan but don't know who to ask. I haven't had my first midwife appointment yet. Any help appreciated xxx