Might be worth just getting some maternity pads to see you through the worst of it (first few days) as even when i said to my sister about one, she laughed and said no two in one go
Its going to be a lot of blood by the sounds of it, nothing compared to a heavy period and the last thing you want to be doing is changing pads every half hour or whatever it would be.
Obviously we are all different and will lose a different amount of blood, but for the sake of a few quid, i would go for the maternity pads.x