thank you for your query.
irregulr periods are common complaits in women and oc pills ar one method used to correct them. however some irregularities can be noted once you start taking them but the periods will normalise in a couple of cycles.
brown discharge can be due to many conditions like endometriosis
. i would advise you to consult your gynecologist in this regard and evaluate the same.
as of your pregancy status you can do a pregancy test to know your status.
you can stop oc pills six months before you want to concieve.
i hope i have answered your query.