I hv facing some strange problems fr dh last few months, there r some blackish liquid r coimng frm my nippls?

from last few months , when i press my or nippels , there r some blackish liquid is coming ,which is not painfull or any kind of elergy . but i wants to know what , how n why it is happning to me . i m so depressed about this. plz do a kind help reagarding above.