help?

So I had a d/c on the 4th and I've been super tired recently, we've been ttc but also kind of just going with the flow idk how to explain that. We aren't trying but were not, not trying. We aren't using contraception though. I have a small spot of blood on my underwear, haven't had cramps or anything like that to indicate my period is coming. I have endometriosis so I'm normally in a hella lot of pain, I was 10w when my baby stopped growing and my d/c was at 12w 4d. I was wondering if this could potentially be implantation bleeding? Am I just going crazy because I'm so hurt still? When should i test to be sure?