My period ended on Feb. 3rd and now I noticed I am having a black tar like discharge.  Mainly when I wipe, but two days ago it was heavy enough to wear a panty liner.  I had cramps last Friday in which I thought I would get my period again even though it had just ended. The cramps are very sporadiac now if at all.  I have never been regular and usually go about 35-55 days between cycles.  Should these be cause for concern or just a possibility it is left over from previos menstrual cycle or normal prior to ovulation?