Bleeding!

Last night I saw blood and now I'm beyond terrified. I have a routine scan Friday morning so doubt I could get in any earlier even if I rang the midwife. I feel so so sick but now I'm wondering if it's fear rather than extreme pregnancy nausea. I have a low down backache (had that in the previous weeks though). No cramping or pain. How am I going to cope until Friday, this is agonising!