Grasping at straws

Aloha ladies, I'm in need of some support and sticky baby dust. DH and I have been trying since June for our rainbow baby after a miscarriage in March. In the last couple of days I have had this metallic taste in my mouth and after some research I found it could be an early sign of pregnancy. But this morning (2 days till AF) my temp went down almost a whole degree. It's DPO 12 and I'm hoping against hope it's a late inplantation dip. Success stories would be helpful and positive thought greatly appreciated.