Am I Having the Symtoms of Pregnancy?

I had a miscarriage (I fell down stairs) on nov.30 me and my boy friend have already started trying again they told me I should get my period in 4-6 weeks so 4 weeks would have been dec.28 but I started spotting on the dec.27? It started out really light but the next day got darker but was only dark for about 3 days out of the 6 this was not like a normal period it was brown with dark red like old blood this was not like a normal period at all could this be because I just lost my last pregnancy? I also had some blood clots which I thought maybe it could just be from what was left from when I lost the baby it looked like old blood to, now a couple days after I stopped bleeding I started spotting with cramps but no blood clots just a light pink/brown that you can only see when I wipe and a little in my panties I am sure we had sex when I would have been ovulating we really want to have a baby and was hoping that what I am experiencing is implantation, is there any other signs of implantation or is bleeding the only one? please if any one has gone through this please respond back ASAP I want to take a hpt but the dr. said it would still show up pregnant I have one more week to go tell I am at the 6 week point and he says it can still show up pregnant thin to please help!!!