I Had The Mirena Iud Put In Tuesday And Right

I had the mirena iud put in Tuesday and right after it was put in I had really bad abdominal pain and after it got better during the same day I went to take a number 2 and my stool was very dark brown. It has been very dark brown since I got the mirena put in. Is this normal or is this a concern? And does this has to do with anything the mirena with my stool?