you cannot have committed a mortal sin without knowledge, consent and act of the will, so how can you not know whether or not you are in a state of mortal sin? In any case, your confession should always end with, for these and for all my sins I am heartily sorry, act of contrition etc.
DISCLAIMER: Catholic Answers has turned over the archive to Catholic-Questions.org and no longer owns, manages, or moderates the forums. For additional apologetics resources please visit www.catholic.com.