I was two days late on my last menstrual cycle which was supposed to come April 1st, 2012 and when it did come it was very light (normally heavy and last 7 days). This one lasted 4 days and was light with really bad cramps. I experienced tender nipples and swollen breast along with fatigue and nausea up to two weeks before it came. And during the last couple of days on it I was experiencing brown discharge which I never do. I took a pregnancy test yesterday because I had been having sharp pains in my lower abdomen and the test came back negative. Is it possible I am pregnant?

It is possible, it is also possible to be a dozen other things.
I would wait a week and try another pregnancy test, and be sure and use the first urine of the morning. If it is still negative, visit your doctor to see other possible causes.