Brown spoting before and after period and blood in stool *explicit*?

I have had a misscarriage before. I know almost 100% that I was pregnant this past month. I had all the symptoms and I just knew. I had a light pink bleeding a few days before my period was supposed to start and then it turned to a light brown kind of muccasy, only when I wiped. Then low and behold I got my period so I read up and it could be a chemical pregnancy. So then, after my period was done I got that light brown again just when I wipe. But my period is over. Then this morning, I seem to also have almost light a dark brown blood in my stool or that's what it seems to be. I also have been having almost black colored stools for like a week now. Can anyone help? I am starting to get worried. :-( I did take a pregnancy test when the pink blood started and it was negative. Nothing hurts either but nothing like this has ever happened to me before. Thanks for all your help in advance.