collegegirl11992, it can be breakthrough spotting/bleeding. It is one of the pesky side effects of the pill. It will normally just disappear as your body adjusts to the hormones. If it does not subside, speak to your doctor.
Brown blood is normally a sign that it is a bit older than fresh blood and that it maybe does not contain the anti-clotting agent that your uterus lining gives off during menstruation. this is typical for spotting where the drops might take a while to get out.
If you think something is wrong, see a doctor. You should also test for pregnancy around March 20, just to make sure.
Best of luck!