I'm not pregnant , but milk is coming out from my breast. what is the cause?

Uncertain.: Possible causes for galactorrhea include but are not limited to use of birth control pills, tricyclic antidepressants, antipsychotic meds, some sedatives, fennel, anise, fenugreek, some hypertension meds, cocaine, opioids, hypothyroidism, prolactinoma, renal dz, pregnancy, testosterone deficiency in men ; significant breast stimulation.