It can be. Brown blood is old blood and is usually a sign that your body is flushing out anything in there so that it's nice and clean for the baby to grow.
Spotting can also be normal, as well as light cramping. If you start to experience anything more painful and/or the bleeding becomes more heavy then you need to seek medical advice.
I had brown spotting and sumtimes the color varied bewtween brown, tan,brown-red it lasted for about a week. I sumtimes had pinkish/redish discharge after sex but that was about it. If u have bright red blood w/cramps call ur ob asap or go to the er asap u might be having a miscarriage or a threatened miscarriage.