It is not common to have any kind of vaginal discharge a week before having a period. Brown discharge could be blood... or could indicate something else. Your gynecologist should see that discharge and perform a basic gynecological examination (vaginal examination, Pap-test and vaginal ultrasound).
Low sperm count (oligospermia) can be due to various reasons and treatment depends upon the cause. Sometimes when a low sperm count can not be countered, there are some assisted reproductive techniques used for achieving conception.