My last period was in September 2010 during the last week I was on because microgynon but hadn't taken any since last September I did not receive a period for October and November until yesterday I noticed a brown vignal discharge and today was the same thing just was wondering whether Im pregnant or not I really want to have a child now but I do have irregular periods at time.

Since you have irregular periods, it could just be due to that. Some women will have some brownish discharge just before or after a period.

Only way to know if pregnancy is the cause would be to try a test. Maybe give it a few more days and see if this turns out to be a period starting or not and then test if need be.