Implantation bleeding??

Hey ladies so over a month ago i got my Merina IUD removed, I only had it for 8 months roughly. I always still got my period when i has the IUD in place, anyways.. Since i’ve gotten it removed me and my hubby have been ttc! I took a pregnancy test about two weeks ago, and it came back as a faint positive but was not sure because some people were telling me it was invalid/due run. I haven’t tested since, but the last few days i’ve had cramps when i moved a certain way, but thought that it was just from me working out. But i have been noticing i’ve been having to go # 2 a lot sorry tmi lol but with my last pregnancy that was one of my symptoms. Earlier today i’ve had some cramps and followed by why i thought was my period, but it was super light and not super red. I put a tampon in and took it out after 30 min and there was nothing on it just brown, old blood. Could i have experienced implantation bleeding??