Hi Ladies, just wanted to give you an update on my situation. First, thank you for all your lovely messages last week; they made the world seem a little less bleak. 
Quick recap - last Sunday on OTD I had a BFP, then on the Tuesday I started to bleed. It went from a bit of spotting to full blown AF (red blood, terrible cramps) within a couple of hours. I cried for 2 days. I said my goodbyes, I accepted the crapness of it all and I made my plans to try again.
On the Friday I took another test - I wanted to see a faded line so I could phone up the clinic and confirm it had been a CP and make an appointment to talk next steps. The line was just as dark as OTD. Maybe it was too soon to tell and the hormone was still in my body? So back in limbo, still bleeding normal AF levels.
The past few days I have been having tenderness around my right hip so have worked myself up into a state about ectopic pregnancy. This morning I took another test hoping for a change (never wished for a BFN before). It is still a strong positive. So I phoned my clinic and spoke to a nurse and then a doctor who was wonderfully blarse about the whole thing. Basically said unless I think I'm dying and have more pain than a paracetamol can handle (in which case I should go to A&E) I should just wait for my scan (which is in 2 weeks). Loads of women have bleeding, some of it heavy, it settles down eventually. 
(oh I see, really sorry to have wasted your time!)
So now I am back in limbo again. I am still bleeding and have stomach cramps. I don't feel pregnant, physically and mentally I feel very detached. I plan to try and wait another week before testing again (we are away for a long weekend so have some distraction) and if it's still positive then I guess I just have to see what the scan shows. I will keep you posted.
There have been a few BFNs over the past week - thinking of you all and wishing you well xx