What Causes Intermittent Bleeding With Severe Mood Swings When On Clomid?

I am on clomid. My periods are December 12 to 16, 2010. January 10 to 14, 2011. February 9 to 13, 2011 and March 16 to 20, 2011. Next on April the 13th I started bleeding a little but first brownish color, then the next day normal red blood, BUT instead of my 5 day cycle I it lasted for 3 days could I be pregnant and I have some symptoms also. Like sore breast, moods swings, headaches, urinating more often then usual.