Hi everyone thanks for all the positive thoughts and 

Had my booking in appointment this morning and I think it is all fine. No bleeding at all today (although I've been obsessively checking all day).
My midwife said not to be concerned about the bleeding unless it is sustained, heavy and accompanied by abdominal pain. Seeings as it was only a bit last night (was very shocked by the red though) and it didn't continue overnight - she said it was normal and could be due to the uterus shifting and stretching or from baby settling in the lining. She also said light bleeding could happen after intercourse (cue looks and eyebrow movement from DH)
Basically the advice is try not to worry but if it happens again and it is heavy and sustained to contact A&E or local EPU. So I am on underpants patrol until further notice.
The rest of the appointment was boring with lots of tickbox questions but by the end of it I was happily reassured enough to enjoy the rest of my day off and had a nice lunch date with DH.
You ladies are the best here though you are my lifeline! Spoke to my mum and she said not to worry about a little bleeding and she should know she's had 5 kids!!