Damn, was going to suggest Kings College in Denmark Hill Camberwell (South London)but it will be a trek for you. They have a walk-in epu mon-fri (you don't need an appt.)and if you get there at 8.30 you will defo be seen and I have never had to beg to be scanned. St. Thomas's,SE1 also have one which is open longer hours but I think you have to ring for an appt. Might be easier for you to get there by train? Is Brighton likely to have something?
I know everyone views these things differently. For me, it was important to be scanned asap so that I knew what I was dealing with. Other women prefer to wait it out (what will be will be etc.). Do what feels best. By the way, lots of women bring their kids along to the epu - I took ds with me twice.
Really hoping everything is ok. Dunno if it's reassuring to say (or bloody annoying) but Kerry Katona had a big bleed to the point where she announced a m/c, then found baby was ok. She is the most recent example I could think of. Apologies if that's a highly irritating example. Maybe Mrs McJnr's one was better