Okay so two days ago I started getting back pains and a bit of cramping, so I knew I was going to get my period soon. So yesterday I went to the restroom and I had dark brown spotting(discharge), and eventually my period came. This has never happened to me and I'm a bit worried about it. My period came already and it's normal and it was on the exact day which was on the 11th. Is this brown spotting bad ? I have been exercising A LOT lately idk if it has something to do with it ? HELP PLEASE