What Causes Brown Discharge?

Hi, may I answer your health queries right now ? Please type your query here... Ok I had my period the week of april 4 2011. Today is april 22 I'm due for my period may 2. I had some spotting brown discharge looking on april 20. I took one test april 18 negative. So should I take another one now on april 23 or should I wait longer? Also been feeling queasy. Could I be pregnant???? Had sex april 9 condom broke