Good luck for your scan today!
I had bleeding in both my last pregnancy and this one. All the way through first trimester. They never found the cause in my last pregnancy, it wasn't affecting the baby and everything was fine.
In this one they've not found the cause either, but again, baby seems fine. I have had 5 scans so far, all at EPU, although you've got to be rather forceful! My official 12w scan is on Thursday. I know baby is still there though as i bought a doppler for my peace of mind which really helps.
My last bleeding was just over a week ago, i was just over 11 weeks and it was a Saturday, i went to A&E and after 4 hours waiting they said that it was against their policy to scan on weekends! ridiculous! I had to wait until the Tuesday after.