My sister had awful clotting and bleeding until week 13, so don't give up yet. She swore it was all over so many times (didn't tell me about the pregnancy until week 12 because she didn't want to upset me given my history just incase she did lose the baby). She is due in a couple of weeks and the baby is fine. Your doc is right, it could have been in decline which you won't know until you have a second BT, but don't give up just yet
Are you having another BT to check what's happening?
xx