I've recently been losing brown blood 3 days before my period, i have no sign of my period coming. any ideas ?

No worries: Brown indicates old blood (not heavy bleeding) If you are not on a hormonal birth control, it simply means that you had a shift in your hormones three days earlier causing a small shedding of the endometrium. Without pain, increased cramping or anything malodorous, I would not worry about it. The corpus luteum don't always behave as predictably as we suspect. Get an ultrasound if its persistent.