Oh you poor thing. Its such a horrible shock, isn't it? Have you got someone who can be with you tonight and tomorrow?
If it does happen naturally, I found that the bleeding got heavier, over a few hours and it also got quite painful. It lasted a couple of hours and then the bleeding and pain started to subside again and I could tell it was all over, if you see what I mean, although I did bleed like a period for a week or so after that. I also felt quite physically sick, which might have been the shock.
If you haven't already, I'd get hold of some really good heavy nighttime pads (better absorbancy than daytime ones) and some painkillers plus a hot water bottle in case it helps. I was told not to use tampons or have a bath in case of infection, but I did have a hot bath a few hours later as I felt I really needed it. And a good box set so I could lie on the sofa and try and distract myself a bit.
As for the surgery...I was very, very scared, more of having a general anaesthetic than the actual procedure, i think, but as soon as I came round after the surgery I felt very relieved it was all over, and I had a slight crampy pain that day and bled slightly for 3 or 4 days but nothing like as heavy as a period.
I was quite weepy and vulnerable afterwards, and had to try and remember to be gentle with myself.
(I was advised to take a pregnancy test 2 weeks later just to check it was negative.)