Brown CM or something

Sarah • 24 *found out 7/31/14* Erik Born 3/30/15!
I think it's spotting. It's not any sort of red. No painful cramps. Just brown discharge stuff. Started two days before I was supposed to get my period and found out I was pregnant on the second day of my pissed period. I'm 4 weeks and 3 days. Is this normal? When does it end? It's kinda freaking me out.