late implantation

madison
When is the latest one has noticed implantation? 
The reason I'm asking is I miscarried on Christmas Day and it finished on the 26th, I had unprotected sex on the first and then I waited a few days to have sex again. Anyways I lost all my symptoms of pregnancy before I miscarried last time and like 2 weeks after we had sex they came back (sore boobs, emotional, cravings and sickness) (I never have boob pain of any symptoms for my period) I was told last time I am one of those sensitive women who feel everything early in pregnancy. Last time I tested and tested getting faint lines that only I could see until I got my bfp. Well this time I have been testing and I see a faint line but it's tough to tell. I don't know if I just implanted late because I had brown discharge with some pink light when I wiped on the 29th and I still am getting faint positives. When I am expecting my period I have horrible pains with an immediate flow of blood and it is so bloody. I'd really like some advice as I'm confused.