I don't want to give you false hope but it's entirely possible to bleed quite a bit and go on to have a normal pregnancy, I had this with my DD and now she's a very active 16 month old! I had lots of implantation bleeding, then more bleeding at six weeks, eight weeks and ten weeks - not going to lie to you, it was sh*t!! But after ten weeks it all stopped and was all good from there in.
Fingers crossed this one hangs on in there for you hon!
xx